function isDate(val,format) {
	var date = getDateFromFormat(val,format);
	if (date==0)
		return false;
	return true;
}

function _isInteger(val) {
	var digits="1234567890";
	for (var i=0; i < val.length; i++) {
		if (digits.indexOf(val.charAt(i))==-1) { return false; }
		}
	return true;
}

function _getInt(str,i,minlength,maxlength) {
	for (var x=maxlength; x>=minlength; x--) {
		var token=str.substring(i,i+x);
		if (token.length < minlength) { return null; }
		if (_isInteger(token)) { return token; }
		}
	return null;
}

function getDateFromFormat(val,format) {
	val=val+"";
	format=format+"";
	var i_val=0;
	var i_format=0;
	var c="";
	var token="";
	var token2="";
	var x,y;
	var now=new Date();
	var year=now.getYear();
	var month=now.getMonth()+1;
	var date=1;
	var hh=now.getHours();
	var mm=now.getMinutes();
	var ss=now.getSeconds();
	var ampm="";

	while (i_format < format.length) {
		// Get next token from format string
		c=format.charAt(i_format);
		token="";
		while ((format.charAt(i_format)==c) && (i_format < format.length)) {
			token += format.charAt(i_format++);
			}
		// Extract contents of value based on format token
		if (token=="yyyy" || token=="yy" || token=="y") {
			if (token=="yyyy") { x=4;y=4; }
			if (token=="yy")   { x=2;y=2; }
			if (token=="y")    { x=2;y=4; }
			year=_getInt(val,i_val,x,y);
			if (year==null) { return 0; }
			i_val += year.length;
			if (year.length==2) {
				if (year > 70) { year=1900+(year-0); }
				else { year=2000+(year-0); }
				}
			}
		else if (token=="MMM"||token=="NNN"){
			month=0;
			for (var i=0; i<MONTH_NAMES.length; i++) {
				var month_name=MONTH_NAMES[i];
				if (val.substring(i_val,i_val+month_name.length).toLowerCase()==month_name.toLowerCase()) {
					if (token=="MMM"||(token=="NNN"&&i>11)) {
						month=i+1;
						if (month>12) { month -= 12; }
						i_val += month_name.length;
						break;
						}
					}
				}
			if ((month < 1)||(month>12)){return 0;}
			}
		else if (token=="EE"||token=="E"){
			for (var i=0; i<DAY_NAMES.length; i++) {
				var day_name=DAY_NAMES[i];
				if (val.substring(i_val,i_val+day_name.length).toLowerCase()==day_name.toLowerCase()) {
					i_val += day_name.length;
					break;
					}
				}
			}
		else if (token=="MM"||token=="M") {
			month=_getInt(val,i_val,token.length,2);
			if(month==null||(month<1)||(month>12)){return 0;}
			i_val+=month.length;}
		else if (token=="dd"||token=="d") {
			date=_getInt(val,i_val,token.length,2);
			if(date==null||(date<1)||(date>31)){return 0;}
			i_val+=date.length;}
		else if (token=="hh"||token=="h") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>12)){return 0;}
			i_val+=hh.length;}
		else if (token=="HH"||token=="H") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>23)){return 0;}
			i_val+=hh.length;}
		else if (token=="KK"||token=="K") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<0)||(hh>11)){return 0;}
			i_val+=hh.length;}
		else if (token=="kk"||token=="k") {
			hh=_getInt(val,i_val,token.length,2);
			if(hh==null||(hh<1)||(hh>24)){return 0;}
			i_val+=hh.length;hh--;}
		else if (token=="mm"||token=="m") {
			mm=_getInt(val,i_val,token.length,2);
			if(mm==null||(mm<0)||(mm>59)){return 0;}
			i_val+=mm.length;}
		else if (token=="ss"||token=="s") {
			ss=_getInt(val,i_val,token.length,2);
			if(ss==null||(ss<0)||(ss>59)){return 0;}
			i_val+=ss.length;}
		else if (token=="a") {
			if (val.substring(i_val,i_val+2).toLowerCase()=="am") {ampm="AM";}
			else if (val.substring(i_val,i_val+2).toLowerCase()=="pm") {ampm="PM";}
			else {return 0;}
			i_val+=2;}
		else {
			if (val.substring(i_val,i_val+token.length)!=token) {return 0;}
			else {i_val+=token.length;}
			}
		}
	// If there are any trailing characters left in the value, it doesn't match
	if (i_val != val.length) { return 0; }
	// Is date valid for month?
	if (month==2) {
		// Check for leap year
		if ( ( (year%4==0)&&(year%100 != 0) ) || (year%400==0) ) { // leap year
			if (date > 29){ return 0; }
			}
		else { if (date > 28) { return 0; } }
		}
	if ((month==4)||(month==6)||(month==9)||(month==11)) {
		if (date > 30) { return 0; }
		}
	// Correct hours value
	if (hh<12 && ampm=="PM") { hh=hh-0+12; }
	else if (hh>11 && ampm=="AM") { hh-=12; }
	var newdate=new Date(year,month-1,date,hh,mm,ss);
	return newdate.getTime();
}

function isValidPhone(element, errMsg){
	var rexpPhone = /^\+?[0-9]{6,12}$/;
	if(element.value.match(rexpPhone))
		return true;
	alert(errMsg);
	element.focus();
	return false;
}

function isValidPSC(element, errMsg){
	var rexpPSC = /^[0-9]{5}$/;
	if(element.value.match(rexpPSC))
		return true;
	alert(errMsg);
	element.focus();
	return false;
}

function isValidDate(element, errMsg){
	if(isDate(element.value, "d. M. y"))
		return true;
	alert(errMsg);
	element.focus();
	return false;
}

function isFilled(element, errMsg){
	if(element.value.length > 0)
		return true;
	alert(errMsg);
	element.focus();
	return false;
}

function ordfvalidate(){
	var chname  = document.getElementsByName('chname')[0];
	var chsname = document.getElementsByName('chsname')[0];
	var msname  = document.getElementsByName('msname')[0];
	var dateborn= document.getElementsByName('dateborn')[0];
	var street  = document.getElementsByName('street')[0];
	var city    = document.getElementsByName('city')[0];
	var psc     = document.getElementsByName('psc')[0];
	var phone   = document.getElementsByName('phone')[0];
	var email   = document.getElementsByName('email')[0];
	var school  = document.getElementsByName('school')[0];
	var cclass  = document.getElementsByName('class')[0];
	var problem = document.getElementsByName('problem')[0];

	if (isFilled(chname, "Prosím vyplňte jméno dítěte"))
	if (isFilled(chsname, "Prosím vyplňte příjmení dítěte"))
	if (isValidDate(dateborn, "Prosím vyplňte korektně datum narození dítěte.\nDatum narození zadávejte ve formátu den, měsíc, rok\n(d. m. rrrr) včetně teček a mezer."))
	if (isFilled(street, "Prosím vyplňte jméno ulice a č.p."))
	if (isFilled(city,   "Prosím doplňte město"))
	if (isValidPSC(psc,  "Prosím doplňte PSČ\n(Pouze 5 čísel - bez mezer)"))
	if (isValidPhone(phone,"Prosím doplňte telefon\n(Pouze čísla - bez mezer)"))
	if (isFilled(problem,"Prosím doplňte popis problému"))
		return true;
	return false;
}

function suggfvalidate(){
	var pname  = document.getElementsByName('uname')[0];
	var email   = document.getElementsByName('uemail')[0];
	var suggtext = document.getElementsByName('suggtext')[0];

	if (isFilled(pname, "Prosím vyplňte své jméno"))
	if (isFilled(suggtext,"Prosím doplňte text připomínky"))
		return true;
	return false;
}