function datediff(date1,date2)
{

var getdate1=new Date(date1)
var getdate2=new Date(date2)


year1=(getdate1.getFullYear())
month1=(getdate1.getMonth()+1)
day1=(getdate1.getDate())

year2=(getdate2.getFullYear())
month2=(getdate2.getMonth()+1)
day2=(getdate2.getDate())

date1=year1 + "/" + day1 + "/" + month1
date2=year2 + "/" + day2 + "/" + month2

var getdate1=new Date(date1)
var getdate2=new Date(date2)

//document.write(date1 + "<br>" + date2 )

var one_day=24*60*60*1000
//Calculate difference btw the two dates, and convert to days
var result=Math.ceil((getdate2.getTime()-getdate1.getTime())/(one_day))
return result;

}




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

function isInteger(s){
	var i;
    for (i = 0; i < s.length; i++){   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag){
	var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to 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){
	// February has 29 days in any year evenly divisible by four,
    // EXCEPT for centurial years which are not also divisible by 400.
    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,dtlevel) //dtlevel means the complete date of only mm-yyyy if dtlevel=2 then (mm-yyyy) and if dtlevel=3 then (dd-mm-yyyy)
{
	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)
	}
//	day=parseInt(strDay)
//	month=parseInt(strMonth)
day=parseInt(strMonth)
month=parseInt(strDay)

	year=parseInt(strYr)
	if (pos1==-1 || pos2==-1){
		
		if (dtlevel==2){
		alert("The date format should be : mm/yyyy \n please also check the seperator it must be  ( / ) ")}
		else{
		alert("The date format should be : mm/dd/yyyy \n please also check the seperator it must be  ( / ) ")}
		
		return false;
	}
	if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
		alert("Please enter a valid day")
		return false;
	}

	if (strMonth.length<1 || month<1 || month>12){
		alert("Please enter a valid month")
		return false;
	}
	if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
		alert("Please enter a valid 4 digit year between "+minYear+" and "+maxYear)
		return false;
	}
	if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
		alert("Please enter a valid date")
		return false;
	}
//return true
}


//===================================================================================


function validate_registration()
	{
		if(frmSignUp.login_name.value=="")
		{
			alert("Please enter login name.");
			frmSignUp.login_name.focus()
			return false;
		}
		else if(frmSignUp.u_name.value=="")
		{
			alert("Please enter you name.");
			frmSignUp.u_name.focus()
			return false;
		}
		else if(frmSignUp.dept.value=="")
		{
			alert("Please enter your department.");
			frmSignUp.dept.focus()
			return false;
		}
			else if(frmSignUp.telephone.value=="")
		{
			alert("Please enter your telephone.");
			frmSignUp.telephone.focus()
			return false;
		}
		else if(frmSignUp.su_name.value=="")
		{
			alert("Please enter your supervisor's name.");
			frmSignUp.su_name.focus()
			return false;
		}
		else if(frmSignUp.su_email.value=="")
		{
			alert("Please enter your supervisor's email.");
			frmSignUp.su_email.focus()
			return false;
		}		
		su_email=frmSignUp.su_email.value
		if (su_email.indexOf('@')<1)
		{
			alert("Please enter a valid email address for your supervisor.");
			frmSignUp.su_email.focus()
			return false;
		}
		if (su_email.indexOf('.')<3)
		{
			alert("Please enter a valid email address for your supervisor.");
			frmSignUp.su_email.focus()
			return false;
		}
		else if(frmSignUp.email.value=="")
		{
			alert("Please enter your email address.");
			frmSignUp.email.focus()
			return false;
		}
		email=frmSignUp.email.value
		if (email.indexOf('@')<1)
		{
			alert("Please enter a valid email address.");
			frmSignUp.email.focus()
			return false;
		}
		if (email.indexOf('.')<3)
		{
			alert("Please enter a valid email address.");
			frmSignUp.email.focus()
			return false;
		}
}



//=======================================================================

function validate_search()
{
	if(frmSearch.start_date.value!="")
	{
		if(isDate(frmSearch.start_date.value,3)==false) 
		{
			frmSearch.start_date.focus()
			return false;
		}
	}

	if(frmSearch.end_date.value!="")
	{
		if(isDate(frmSearch.end_date.value,3)==false) 
		{
			frmSearch.end_date.focus()
			return false;
		}
	}


}