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)
{
	var daysInMonth = DaysArray(12);
	var pos1=dtStr.indexOf(dtCh);
	var pos2=dtStr.indexOf(dtCh,pos1+1);
	var strMonth=dtStr.substring(0,pos1);
	var strDay=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('The date format should be : mm/dd/yyyy');
		return false;
	}
	if (strMonth.length<1 || month<1 || month>12){
		alert('Please enter a valid month')
		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 (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 validateAppl()
{
   var appName=document.applicationForm.appName.value; 
   var icNo=document.applicationForm.icNo.value; 
   var textfield=document.applicationForm.textfield.value;
   var race=document.applicationForm.race.value;
   var citizenship=document.applicationForm.citizenship.value;
   var address1=document.applicationForm.address1.value;
   var aliaspos=document.applicationForm.email.value.indexOf('@');
   var dotpos=document.applicationForm.email.value.lastIndexOf('.');
   var mobPhone=document.applicationForm.mobPhone.value;
   var kin=document.applicationForm.kin.value;
   var relationship=document.applicationForm.relationship.value;
   var telNoKin=document.applicationForm.telNoKin.value;
   var school1=document.applicationForm.school1.value;
   
   
   if (appName == '')
   {
		alert('Please enter your name.');
   		return false;
   }
   if (icNo == '')
   {
		alert('Please enter your NRIC/Passport No.');
   		return false;
   }
   if (textfield == '')
   {
		alert('Please enter Place of Birth.');
   		return false;
   }
   if (race == '')
   {
		alert('Please enter your race.');
   		return false;
   }
   if (citizenship == '')
   {
		alert('Please enter your citizenship.');
   		return false;
   }
   if (address1 == '')
   {
   		alert('Please enter your Permanent Address');
   		return false;
   }
   if (aliaspos == -1 || dotpos==-1)
   {
		alert('Please enter a valid email');
		return false;
   }
   if (mobPhone == '')
   {
   		alert('Please enter your contact number.');
   		return false;
   }
   if (kin == '')
   {
   		alert('Please enter Name of Next of Kin.');
   		return false;
   }
   if (relationship == '')
   {
   		alert('Please enter relationship of Next of Kin.');
   		return false;
   }
   if (telNoKin == '')
   {
   		alert('Please enter contact number of Next of Kin.');
   		return false;
   }
   if (school1 == '')
   {
   		alert('Please enter your academic background.');
   		return false;
   }
   
   return true;
}