function expr(x) {
	return eval('('+x+')');
}

// the opposite of `expr'
// - expr(repr(x)) should be equal to x for any constant expression x
function repr(x) {
	var y = '';
	if (x === undefined) {
		return 'undefined';  // BEWARE! JSON does not know about 'undefined'
	} else if (x === null) {
		return 'null';
	} else if (typeof x === 'boolean') {
		return x ? 'true' : 'false';
	} else if (typeof x === 'number') {
		return String(x);
	} else if (typeof x === 'string') {
		for (var i = 0 ; i < x.length ; ++i) {
			var c = x.charAt(i);
			switch (c) {
			case '\b': c = '\\b'; break;
			case '\t': c = '\\t'; break;
			case '\n': c = '\\n'; break;
			case '\r': c = '\\r'; break;
			case '\f': c = '\\f'; break;
			case '\v': c = '\\v'; break;
			case '"': c = '\\"'; break;
			case '\\': c = '\\\\'; break;
			}
			y += c;
		}
		return '"'+y+'"';
	} else if (x instanceof Array) {
		for (var i = 0 ; i < x.length ; ++i) {
			if (i) y += ',';
			y += repr(x[i]);
		}
		return '['+y+']';
	} else {
		var i = 0;
		for (var key in x) {
			if (i) y += ','; else ++i;
			y += repr(key) + ':' + repr(x[key]);
		}
		return '{'+y+'}';
	}
}

function trim(s) {
	return (/^\s*(.*?)\s*/.exec(s))[1];
}

function map(a,fun) {
	var b = [];
	for (var i = 0 ; i < a.length ; ++i)
		b.push(fun(a[i]));
	return b;
}

function range(a,b,c) {
	var x = [];
	if (b === undefined) {
		for (var i = 0 ; i < a ; ++i)
			x.push(i);
	} else if (c === undefined) {
		for (var i = a ; i < b ; ++i)
			x.push(i);
	} else if (a<b) {
		for (var i = a ; i < b ; i += c)
			x.push(i);
	} else {
		for (var i = a+c ; i >= b ; i += c)
			x.push(i);
	}
	return x;
}

function maxf(a,f) {
	var m = a[0];
	var fm = f(m);

	for (var i = 1 ; i < a.length ; ++i) {
		var ai = a[i];
		var fai = f(ai);
		if (fm < fai) {
			m = ai;
			fm = fai;
		}
	}

	return m;
}

function array_has(arr,x) {
	for (var i = 0 ; i < arr.length ; ++i) {
		if (arr[i] == x) {
			return i;
		}
	}
	return -1;
}

function array_merge(a,b) {  // more like `object_merge'
	var c = {};
	for (var n in a) c[n] = a[n];
	for (var n in b) c[n] = b[n];
	return c;
}

function html(str) {
	if (str == null)
		return '';

	if (typeof str != 'string')
		str = String(str);

	var y = '';
	for (var i = 0 ; i < str.length ; ++i) {
		var c = str.charAt(i);
		switch (c) {
		case '&': c = '&amp;'; break;
		case '<': c = '&lt;'; break;
		case '>': c = '&gt;'; break;
		case '"': c = '&quot;'; break;
		case "'": c = '&#039;'; break;
		}
		y = y + c;
	}
	return y;
}

// (flags&1) : for all smaller unknowns (months days hours etc.) assume maximum (and not minimum) possible values
//             (larger unknowns are always decided as if we were looking for the minimums of the smaller unknowns, so with/without 1 gives continuous range)
// (flags&2) : interpret [0]0-[0]0 as `month-year' (and not as `day-month'/`month-day' depending on $PREF_DATE_FORMAT)
// (flags&4) : prefer recent past dates (and not simply nearest dates)
// (flags&8) : interpret [0]0 as year (and not as day)
// ____-__-DD !(flags&8)  FIXME!!!
// ____-MM-DD !(flags&2)
// ___Y-MM-DD
// __YY-MM-DD
// _YYY-MM-DD
// YYYY-MM-DD
// ____-MM-__ never
// ___Y-MM-__ (flags&2)
// __YY-MM-__ (flags&2)
// _YYY-MM-__
// YYYY-MM-__
// ___Y-__-__ (flags&8)
// __YY-__-__ (flags&8)
// _YYY-__-__
// YYYY-__-__
// __:__:__
// hh:__:__
// hh:mm:__
// hh:mm:ss
function parseDate(str, flags) {
	var x = null;

	if ((flags&8) && x == null) {  // optional
		// [y]y
		x = /^\s*(\d\d?)\s*$/.exec(str);
		if (x != null) {
			x = ['',x[1],'','','','',''];
		}
	}
	if ((flags&2) && x == null) {  // optional
		// [m]m-[y]y
		x = /^\s*(\d\d?)\s*[-\/]\s*(\d\d?)\s*$/.exec(str);
		if (x != null) {
			x = ['',x[2],x[1],'','','',''];
		}
	}
	if (x == null) {
		// [m]m-[y]yyy [hours[:minutes[:seconds]]]
		x = /^\s*(\d\d?)\s*[-\/]\s*(\d\d\d\d?)\s*(?:(?:\s|T)\s*(\d\d?)\s*(?::\s*(\d\d?)\s*(?::\s*(\d\d?)\s*)?)?)?$/.exec(str);
		if (x != null) {
			x = ['',x[2],x[1],'',x[3],x[4],x[5]];
		} else {
			// [hours[:minutes[:seconds]]] [m]m-[y]yyy
			x = /^\s*(?:(\d\d?)\s*(?::\s*(\d\d?)\s*(?::\s*(\d\d?)\s*)?)?(?:\s|T)\s*)?(\d\d?)\s*[-\/]\s*(\d\d\d\d?)\s*$/.exec(str);
			if (x != null) {
				x = ['',x[5],x[4],'',x[1],x[2],x[3]];
			}
		}
		if (x == null) {
			// [y]yyy[-[m]m[-[d]d]] [hours[:minutes[:seconds]]]
			x = /^\s*(\d\d\d\d?)\s*(?:[-\/]\s*(\d\d?)\s*(?:[-\/]\s*(\d\d?)\s*(?:(?:\s|T)\s*(\d\d?)\s*(?::\s*(\d\d?)\s*(?::\s*(\d\d?)\s*)?)?)?)?)?(.*?)\s*$/.exec(str);
		}
	}
	if (x == null) {
		// day[-month[-[[[y]y]y]y] [hours[:minutes[:seconds]]]
		// month[-day[-[[[y]y]y]y] [hours[:minutes[:seconds]]]
		x = /^\s*(\d\d?)(?:\s*[-\/]\s*(\d\d?)\s*(?:[-\/]\s*(\d{1,4})\s*?)?)?(?:(?:\s|T)\s*(\d\d?)\s*(?::\s*(\d\d?)\s*(?::\s*(\d\d?)\s*)?)?)?$/.exec(str);
		if (x != null) {
			x = ['',x[3],x[2],x[1],x[4],x[5],x[6]];
			if ( 0 /**/) { var tmp = x[3]; x[3] = x[2]; x[2] = tmp; }
		} else {
			// [hours[:minutes[:seconds]]] day[-month[-[[[y]y]y]y] 
			// [hours[:minutes[:seconds]]] month[-day[-[[[y]y]y]y] 
			x = /^\s*(?:(\d\d?)\s*(?::\s*(\d\d?)\s*(?::\s*(\d\d?)\s*)?)?(?:\s|T)\s*)?(\d\d?)\s*[-\/]\s*(\d\d?)\s*(?:[-\/]\s*(\d{1,4})\s*?)?\s*$/.exec(str);
			if (x != null) {
				x = ['',x[6],x[5],x[4],x[1],x[2],x[3]];
				if ( 0 /**/) { var tmp = x[3]; x[3] = x[2]; x[2] = tmp; }
			}
		}
	}

	var determine_year = function(x,flags) {  // FIXME again
		var cur = new Date();
		var curyear = cur.getFullYear();
		var cury = String(curyear);
		if (x[1]==null || x[1]=='') {
			return new Date().getFullYear();
		} else if (x[1].length<=cury.length) {
			var month = (x[2]!=null&&x[2]!='') ? (parseInt(x[2],10)||null) : null;
			var curmonth = cur.getMonth();
			var day = (x[3]!=null&&x[3]!='') ? (parseInt(x[3],10)||null) : null;
			var curday = cur.getDate();

			var unit = 1;
			for (var i = 0 ; i < x[1].length ; ++i) unit = unit*10;

			var curprefix = (x[1].length<cury.length) ? parseInt(cury.substring(0,cury.length-x[1].length), 10) : 0;
			var nearestyear = null;
			for (var prefix = Math.max(curprefix-1,0) ; prefix <= curprefix+1 ; ++prefix) {
				var year = unit*prefix+parseInt(x[1],10);
				if ( ( !(flags&4) || year<curyear || (year==curyear && (month==null || month<curmonth || (month==curmonth && (day==null || day<curday)))) )
				     && (nearestyear==null || Math.abs(curyear-year)<Math.abs(curyear-nearestyear)) ) {
					nearestyear = year;
				}
			}
			return nearestyear;
		} else {
			return x[1];
		}
	}

	var fill_unknowns = function(x,flags) {  // year is known
		x = map(x.slice(1,7),function(i) { return ((i!=null && i!='') ? (parseInt(i,10)||null) : null); });
		x[1] = (x[1]!=null && x[1]>0) ? x[1]-1 : ((flags&1) ? 11 : 0);
		if (x[3]==null) x[3] = ((flags&1) ? 23 : 0);
		if (x[4]==null) x[4] = ((flags&1) ? 59 : 0);
		if (x[5]==null) x[5] = ((flags&1) ? 59 : 0);

		if (x[2]==null || x[2]==0) {
			if (flags&1) {
				for (x[2]=31 ; x[2]>=28 ; --x[2]) {
					var d = new Date(x[0],x[1],x[2],x[3],x[4],x[5]);
					if (d!=null && d.getDate()==x[2]) {
						break;
					}
				}
			} else {
				x[2] = 1;
			}
		}
		return x;
	}

	if (x!=null && x[3]!='0' && x[3]!='00' && x[2]!='0' && x[2]!='00') {
		x[1] = determine_year(x,flags);
		x = fill_unknowns(x,flags);
		var d = new Date(x[0],x[1],x[2],x[3],x[4],x[5]);
		if (d.getFullYear()==x[0] && d.getMonth()==x[1] && d.getDate()==x[2]
		    && d.getHours()==x[3] && d.getMinutes()==x[4] && d.getSeconds()==x[5]) {
			return d;
		}
	}

	return null;
}
function unparseDate(d, withtime) {
	var Y = String(d.getFullYear());
	var M = String(d.getMonth()+1);
	while (M.length < 2) M = '0'+M;
	var D = String(d.getDate());
	while (D.length < 2) D = '0'+D;

	var h = String(d.getHours());
	while (h.length < 2) h = '0'+h;
	var m = String(d.getMinutes());
	while (m.length < 2) m = '0'+m;
	var s = String(d.getSeconds());
	while (s.length < 2) s = '0'+s;

	if ( 0 /**/) {
		return M+'/'+D+'/'+Y + (withtime ? ' '+h+':'+m+':'+s : '');
	} else {
		return D+'/'+M+'/'+Y + (withtime ? ' '+h+':'+m+':'+s : '');
	}
}


/******************************************************************************/


function toid(x) {
	if (x instanceof Array) {
		return x.join('_');
	} else {
		return String(x);
	}
}

function checkbox(name,label,checked,disabled,onchange) {
	if (checked === undefined) checked=false;
	if (disabled === undefined) disabled=false;
	if (onchange === undefined) onchange='';

	return '<span><input id="'+html(name)+'" type="checkbox" name="'+html(name)+'" value="1"'
		+(checked?' checked="checked"':'')
		+(disabled?' disabled="disabled"':'')
		+(onchange?' onclick="'+html(onchange)+'"':'')
		+' class="tickbox checkbox"'
	+'/>'
		+(label.length?'<label for="'+html(name)+'">'+label+'</label>':'')
	+'</span>';
}

function radio(name,value,label,checked,disabled,onchange) {
	if (checked === undefined) checked=false;
	if (disabled === undefined) disabled=false;
	if (onchange === undefined) onchange='';

	return '<span><input type="radio" id="'+html(name)+html(value)+'" name="'+html(name)+'" value="'+html(value)+'"'
		+(checked?' checked="checked"':'')
		+(disabled?' disabled="disabled"':'')
		+(onchange?' onclick="'+html(onchange)+'"':'')
		+' class="tickbox radio"'
	+'/>'+ (label?'<label for="'+html(name)+html(value)+'">'+label+'</label>':'')+'</span>';
}

function dropdown_opt_text(opt) {
	if (typeof opt == 'string') {
		return opt;
	} else if (opt instanceof Array) {
		return opt[1];
	} else if (opt['text'] != undefined) {
		return opt.text;
	} else if (opt['name'] != undefined) {
		return opt.name;
	} else if (opt['value'] != undefined) {
		return opt.value;
	}
}

function dropdown_opt(opt) {
	if (typeof opt == 'string') {
		return {'value':opt, 'text':dropdown_opt_text(opt)};
	} else if (opt instanceof Array) {
		return {'value':String(opt[0]), 'text':dropdown_opt_text(opt[1])};
	} else if (opt['value'] != undefined) {
		return {'value':opt.value, 'text':dropdown_opt_text(opt)};
	} else if (opt['name'] != undefined) {
		return {'value':opt.name, 'text':dropdown_opt_text(opt)};
	} else if (opt['text'] != undefined) {
		return opt.text;
	}
}

function dropdown_opts(obj) {
	var opts = [];
	if ( ! (obj instanceof Array) ) {
		for (var prop in obj) {
			var x = obj[prop];
			if (typeof x != 'string') {
				x = prop;
			}
			opts.push(dropdown_opt([prop,x]))
		}
	} else {
		for (var i = 0 ; i < obj.length ; ++i)
			opts.push(dropdown_opt(obj[i]));
	}
	return opts;
}

function dropdown(id, value, opts, onchange, extra, onblur) {
	opts = dropdown_opts(opts,extra);
	if (extra !== undefined)
		opts = dropdown_opts(extra).concat(opts);

	var str = '<select id="'+html(id)+'" ';
	if (onchange != null) str += ' onchange="'+html(onchange)+'"';
	if (onblur != null) str += ' onblur="'+html(onblur)+'"';
	str += '>';
	if (extra === undefined) {
		str += '<option value=""></option>';
	}
	for (var i = 0 ; i < opts.length ; ++i) {
		var opt = opts[i];
		str += '<option value="'+html(opt.value)+'"';
		if (value == opt.value) str += ' selected="selected"';
		str += '>'+html(opt.text)+'</option>';
	}
	return str+'</select>';
}

function hidden(id, value) {
	return '<input type="hidden" id="'+html(toid(id))+'" value="'+html(repr(value))+'" />';
}

function input(id, value, length, disabled, onchange, onfocus, onblur, onclick) {
	if (id instanceof Array)
		id = id[0]+'_'+id[1];
	return '<input id="'+html(id)+'"'
		+' value="'+html(value)+'"'
		+(length<0?' size="'+html(-length)+'"':'')
		+(length>0?' maxlength="'+html(length)+'" size="'+html(length)+'"':'')
		+(disabled?' disabled="disabled"':'')
		+(onchange?' onchange="'+html(onchange)+'"':'')
		+(onfocus?' onfocus="'+html(onfocus)+'"':'')
		+(onblur?' onblur="'+html(onblur)+'"':'')
		+(onclick?' onclick="'+html(onclick)+'"':'')
		+' class="textarea"'
	+' />';
}

var __the_calendar__ = null;
function dateinput(id, value, disabled, onchange) {
	if (id instanceof Array)
		id = id[0]+'_'+id[1];

	//return input(id, value, -10, disabled, onchange, 'on_dateinput_focus('+repr(id)+')', 'on_dateinput_blur('+repr(id)+')');
	return input(id, value, -10, disabled, onchange, null, 'on_dateinput_blur('+repr(id)+')')
	       +icon(null, 'app/date.gif','(ημ/νία)', 'on_dateinput_activate('+repr(id)+')');
}
function on_dateinput_activate(id) {
	var el = element(id);
	//el.focus();
	on_dateinput_focus(id);
}
function on_dateinput_focus(id) {
	var el = element(id);

	if (__the_calendar__ != null) {
		__the_calendar__.destroy();
		__the_calendar__ = null;
	}
	__the_calendar__ = new Calendar(1, null,
		function(c, value) {
			element(id).value = value;
			/*if (__the_calendar__ != null) {
				__the_calendar__.hide();
				__the_calendar__.destroy();
				__the_calendar__ = null;
			}*/
		},
		function(c) {
			if (__the_calendar__ != null) {
				__the_calendar__.hide();
				__the_calendar__.destroy();
				__the_calendar__ = null;
			}
		}
	);
	__the_calendar__.weekNumbers = false;
	__the_calendar__.showsTime = false;
	__the_calendar__.create();
	__the_calendar__.parseDate(el.value)
	__the_calendar__.showAtElement(el);
}
function on_dateinput_blur(id) {
	if (__the_calendar__ != null) {
		__the_calendar__.hide();
		__the_calendar__.destroy();
		__the_calendar__ = null;
	}
}

function textarea(name, value, cols, rows, disabled, onchange) {
	var prefix=null;
	if (name instanceof Array) {
		prefix = name[0];
		name = name[1];
	}
	return '<textarea name="'+html(name)+'"'
		+(prefix!==null ? ' id="'+html(prefix+'_'+name)+'"' : '')
		+(cols>0?' cols="'+html(cols)+'"':'')
		+(rows>0?' rows="'+html(rows)+'"':'')
		+(disabled?' disabled="disabled"':'')
		+(onchange?' onchange="'+html(onchange)+'"':'')
		+' class="textarea"'
	+'>'
		+html(value)
	+'</textarea>';
}

function icon(name, filename,alt, onclick) {
	var prefix=null;
	if (name instanceof Array) {
		prefix = name[0];
		name = name[1];
	}
	return '<button'
	        +(name!=null ? ' name="'+html(name)+'"' : '')
		+(prefix!=null ? ' id="'+html(prefix+'_'+name)+'"' : '')
		+' type="button"'
		+' class="button icon"'
		+(onclick?' onclick="'+html(onclick)+'"':'')
	+'>'
		+img(filename,alt)
	+'</button>';
}

function img(filename,alt) {
	return '<img src="'+html(filename)+'" alt="'+html(alt)+'" />'
}


/******************************************************************************/


function element(x,y) {
	var retval;

	if (x !== undefined) {
		if (y !== undefined) {
			try {
				if (y != null) {
					retval = document.forms[x].elements[y];
				} else {
					retval = document.forms[x];
				}
			} catch(x) {
				retval = null;
			}
		} else {
			retval = document.getElementById(x);
		}
	}

	if (typeof retval == 'array') {
		retval = retval[0];
	}

	return retval;
}
function elem(x,y) {
	var retval;

	if (x !== undefined) {
		if (y !== undefined) {
			try {
				if (y != null) {
					retval = document.forms[x].elements[y];
				} else {
					retval = document.forms[x];
				}
			} catch(x) {
				retval = null;
			}
		} else {
			retval = document.getElementById(x);
		}
	}

	if (typeof retval == 'array') {
		retval = retval[0];
	}

	return retval;
}

function remove(x) {
	var xx = (typeof x == 'string') ? element(x) : x;
	xx.parentNode.removeChild(xx);
}
function replace(x,y) {
	var xx = (typeof x == 'string') ? element(x) : x;
	$(xx).replaceWith(y);
}
function append(x,y) {
	xx = (typeof x == 'string') ? element(x) : x;
	$(xx).append(y);
}

function get(x,y) {
	var e = elem(x,y);
	if (e == null) return undefined;
	if (e.value == null) return undefined;
	return expr(e.value);
}
function set(x,y,z) {
	if (z !== undefined) {
		elem(x,y).value = repr(z);
	} else {
		elem(x).value = repr(y);
	}
}

function get_string(x,y) {
	var e = elem(x,y);
	if (e == null) return undefined;
	if (e.value == null) return undefined;
	return e.value;
}
function get_int(x,y) {
	var e = elem(x,y);
	if (e == null) return undefined;
	var result = parseInt((e.value==null?null:e.value), 10);
	if (result != result) return undefined;
	return result;
}
function get_float(x,y) {
	var e = elem(x,y);
	if (e == null) return undefined;
	var result = parseFloat((e.value==null?null:e.value), 10);
	if (result != result) return undefined;
	return result;
}
function get_bool(x,y) {
	var e = elem(x,y);
	if (e == null) return undefined;
	if (e.checked == null) return undefined;
	return e.checked;
}

function timeout(t,f) {
	return setTimeout(f,t);
}


/******************************************************************************/


function urlencode(x) {
	if (typeof x == 'string') {
		return encodeURIComponent(x);
	} else {
		return queryencode(x);
	}
}

function queryencode(stuff) {
	var str = "_ENCODING_=utf-8";
	for (var name in stuff) {
		var val = stuff[name];
		if (val != null) {
			if (typeof val != 'string')
				val = repr(val);
			str += "&"+encodeURIComponent(name)+"="+encodeURIComponent(val);
		}
	}
	return str;
}

function form_data(thing, overrides) {
	if (typeof thing == 'string')
		thing = element(thing);

	if (thing.elements !== undefined && thing.innerHTML !== undefined) {
		var seen = {};
		var str = "_ENCODING_=utf-8";
		for (var i = 0 ; i < thing.elements.length ; ++i) {
			var el=thing.elements[i];
			var name = el.name;
			var value = (overrides!=null && overrides[name]!==undefined) ? overrides[name] : el.value;
			if ( name!=null && name.length>0 && value!=null && ((el.type != "checkbox" && el.type != "radio") || el.checked) ) {
				str += "&"+encodeURIComponent(name) + "=" + encodeURIComponent(value);
			}
			seen[name] = true;
		}
		for (var name in overrides) {
			if ( ! seen[name] ) {
				str += "&"+encodeURIComponent(name) + "=" + encodeURIComponent(overrides[name]);
			}
		}
		return str;
	} else {
		return queryencode(thing);
	}
}

function xhr_make(method, url, async) {
	method = method.toLowerCase();

	var req = null;
	if (window.ActiveXObject) {
		try {
			req = new ActiveXObject("Msxml2.XMLHTTP");
		} catch (e) {
			req = new ActiveXObject("Microsoft.XMLHTTP");
		}
	} else {
		req = new XMLHttpRequest();
	}
	req.open(method, url, async);
	if (method == "post") {
		req.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
	}
	req.setRequestHeader("X-Requested-With", "XMLHttpRequest");
	return req;
}

function xhr_success(req, timeout) {
	return (timeout != "timeout") ? (req.status>=200&&req.status<300) || req.status==304 || req.status==1223 : 0;
}

function request(query, postdata, callback) {
	var url, method, headers;

	if (typeof query == 'string') {
		url = query;
		method = (postdata!=null) ? "post" : "get";
		if (postdata == undefined) {
			postdata = null;
		} else if (typeof postdata != 'string' && postdata!=null) {
			postdata = form_data(postdata);
		}
		headers = [];

	} else if (query instanceof Array) {
		url = query[0];
		method = (postdata!=null) ? "post" : "get";
		headers = query.slice(1);

	} else {
		method = query.method.toLowerCase();

		postdata = form_data(query,postdata);
		if (method == 'post') {
			url = query.action;
		} else {
			url = query.action+'?'+postdata;
			postdata = null;
		}
		headers = [];
	}

	var async = (callback!=undefined);
	var req = xhr_make(method, url, async);
	if (callback != undefined) {
		req.onreadystatechange = function(timeout) {
			if ( req != null && (req.readyState == 4 || timeout == "timeout") ) {
				/*if (!req.getResponseHeader("Date")) {
					var req2 = xhr_make(method, url, true);

					var ifModifiedSince = req.getResponseHeader("Last-Modified");
					ifModifiedSince = (ifModifiedSince) ? ifModifiedSince : new Date(0);	// January 1, 1970
					req2.setRequestHeader("If-Modified-Since", ifModifiedSince);

					req2.send(postdata);
					if (req2.status != 304) {
						req2.onreadystatechange = function(timeout) {
							if ( req2 != null && (req2.readyState == 4 || timeout == "timeout") ) {
								callback(req2, xhr_success(req, timeout));
								req2.onreadystatechange = null;
								req2 = null;
							}
						}
					}
				} else {*/
					callback(req, xhr_success(req, timeout));
					req = null;
				/* } */
			}
		}
	}

	for (var i = 0 ; i < headers.length ; ++i)
		req.setRequestHeader(headers[i][0], headers[i][1]);

	req.send(postdata);
	return req;
}