function openCalendar(field, dateFormat) {
	var found=0;
	var pos=-1;
	while (found == 0) {
		pos++;
		if (document.forms[pos]) {
			if (document.forms[pos] == field.form) {
				found = 1;
			}
		}

		if (pos > 20) {
			pos = -1;
			found = 1;
		}
	}
	
	var curDateStr = "";
	var curDate = parseDate((dateFormat ? dateFormat : "dd/MM/yyyy"), field.value);
	if (curDate != null) {
		curDateStr = "&calyear=" + curDate[0] + "&calmonth=" + curDate[1];
	}
	var winDateSel = window.open("/galaxie/common/calendar/calendar_popup.jsp?fn=" + field.name + "&fp=" + pos + (dateFormat ? "&df=" + dateFormat : "") + curDateStr, "DateSelector", "menubar=no,toolbar=no,scrollbars=auto,resizable=yes,width=250,height=280");
}

function strReplace(pStr, pKey, pValue) {
	return pStr.split(pKey).join(pValue);
}

function removeLeadingZeros(inStr) {
	var res = inStr;
	while (res.length > 0 && res.substring(0,1) == "0") {
		res = res.substring(1);
	}
	return res;
}

function parseDate(patern, value) {	
	var yk = "yyyy";
	var yp = patern.indexOf(yk);
	if (yp == -1) {
		yk = "yyy";
		yp = patern.indexOf(yk);
	}
	if (yp == -1) {
		yk = "yy";
		yp = patern.indexOf(yk);
	}
	
	var mk = "MM"
	var mp = patern.indexOf(mk);
	if (mp == -1) {
		mk = "M";
		mp = patern.indexOf(mk);
	}
	
	var dk = "dd"
	var dp = patern.indexOf(dk);
	if (dp == -1) {
		dk = "d";
		dp = patern.indexOf(dk);
	}
	
	if (yp == -1 || mp == -1 || dp == -1) {
		return null;
	}
	
	var yi=0, mi=0, di=0;
	if (yp < mp && mp < dp) {
		yi = 1; mi = 2; di = 3;
	} else if (mp < yp && yp < dp) {
		yi = 2; mi = 1; di = 3;
	} else if (yp < dp && dp < mp) {
		yi = 1; mi = 3; di = 2;
	} else if (dp < yp && yp < mp) {
		yi = 2; mi = 3; di = 1;
	} else if (mp < dp && dp < yp) {
		yi = 3; mi = 1; di = 2;
	} else if (dp < mp && mp < yp) {
		yi = 3; mi = 2; di = 1;
	}
	
	var strRegExp = patern;
	strRegExp = strReplace(strRegExp, "\\", "\\\\");
	strRegExp = strReplace(strRegExp, "/", "\\/");
	strRegExp = strReplace(strRegExp, "*", "\\*");
	strRegExp = strReplace(strRegExp, "+", "\\+");
	strRegExp = strReplace(strRegExp, "?", "\\?");
	strRegExp = strReplace(strRegExp, ".", "\\.");
	strRegExp = strReplace(strRegExp, dk, "([\\d.]+)");
	strRegExp = strReplace(strRegExp, mk, "([\\d.]+)");
	strRegExp = strReplace(strRegExp, yk, "([\\d.]+)");
	
	var regexpr, yvt, mvt, dvt;
	eval("regexpr = /" + strRegExp + "/");
	yvt = value.replace(regexpr, "$"+yi);
	mvt = value.replace(regexpr, "$"+mi);
	dvt = value.replace(regexpr, "$"+di);
	
	if (yvt == value || mvt == value || dvt == value) {
		return null;
	}
	
	var yv, mv, dv;
	yv = parseInt(removeLeadingZeros(yvt));
	mv = parseInt(removeLeadingZeros(mvt));
	dv = parseInt(removeLeadingZeros(dvt));


	if (isNaN(dv) || isNaN(mv) || isNaN(yv)) {
		return null;
	}
	
	return new Array(yv, mv, dv);
}