var dtCh= "/";
var minYear=1900;
var maxYear=2100;

function isInteger(s){
	var i;
    for (i = 0; i < s.length; i++){   
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    return true;
}

function stripCharsInBag(s, bag){
	var i;
    var returnString = "";
    for (i = 0; i < s.length; i++){   
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function daysInFebruary (year){
    return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}
function DaysArray(n) {
	for (var i = 1; i <= n; i++) {
		this[i] = 31
		if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
		if (i==2) {this[i] = 29}
   } 
   return this
}

function isDate(dtStr){
	var daysInMonth = DaysArray(12)
	var pos1=dtStr.indexOf(dtCh)
	var pos2=dtStr.indexOf(dtCh,pos1+1)
	var strDay=dtStr.substring(0,pos1)
	var strMonth=dtStr.substring(pos1+1,pos2)
	var strYear=dtStr.substring(pos2+1)
	strYr=strYear
	if (strDay.charAt(0)=="0" && strDay.length>1) strDay=strDay.substring(1)
	if (strMonth.charAt(0)=="0" && strMonth.length>1) strMonth=strMonth.substring(1)
	for (var i = 1; i <= 3; i++) {
		if (strYr.charAt(0)=="0" && strYr.length>1) strYr=strYr.substring(1)
	}
	month=parseInt(strMonth)
	day=parseInt(strDay)
	year=parseInt(strYr)
	if (pos1==-1 || pos2==-1){
		alert("Inserire il formato di data : gg/mm/aaaa")
		return false
	}
	if (strMonth.length<1 || month<1 || month>12){
		alert("Inserire un mese valido")
		return false
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		alert("Inserire un giorno valido")
		return false
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		alert("Immettere l'anno a quattro cifre compreso tra "+minYear+" e "+maxYear)
		return false
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		alert("Inserire la data correttamente nel formato gg/mm/aaaa")
		return false
	}
return true
}

function OnlyDate(dt){
if (dt.value!="")
{
	if (isDate(dt.value)==false){
		dt.focus()
		return false
	}
 }
  return true
}

function OnlyNumber(oggetto){	
	iLen1 = oggetto.value.length;
	sStr1 = oggetto.value;
	if (sStr1 != "") {
		for (i=0; i<iLen1; i++){
			sKey = sStr1.charCodeAt(i);
			if ((sKey < 48) || (sKey > 57)){					
				alert("Attenzione! Il campo accetta solo valori numerici!");
				oggetto.focus();
				oggetto.select();
				return false;
				break;
			}
		}
	}
	return true; 
}

function OnlyEmail(oggetto){ 
	strMail = oggetto.value;
	
	if (strMail != ""){
		var EMAIL_reg_exp = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-]{2,})+\.)+([a-zA-Z0-9]{2,})+$/;
		if (!EMAIL_reg_exp.test(strMail)) {
			alert("Indirizzo email non valido!");
			oggetto.focus();
			oggetto.select(); 
			return false;
		}
	}
	return true;
}

function emailCheck (emailStr){
	var email_reg_exp = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-]{2,})+\.)+([a-zA-Z0-9]{2,})+$/;
	if (!email_reg_exp.test(emailStr)) {
		return false;
	}
		
	return true;
	
}