function echeck(str) { 
	var at="@"
	var dot="."
	var lat=str.indexOf(at)
	var lstr=str.length
	var ldot=str.indexOf(dot)
	
	if (str.indexOf(at)==-1)   return false;
	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr) return false;
	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr) return false;
	if (str.indexOf(at,(lat+1))!=-1) return false;
	if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot) return false;
	if (str.indexOf(dot,(lat+2))==-1) return false;
	if (str.indexOf(" ")!=-1) return false;

	return true					
}

function isInteger(s) { 
	if (s=='') return true; 
	var digitsRequired = 7;
	var i; 
	for (i = 0; i < s.length; i++) { 
		var c = s.charAt(i); 
		if (((c < "0") || (c > "9"))) return false; 
	} 
	if (s.length == digitsRequired) { return true; } else { return false; } 
	return true; 
}

function ValidateForm(iN) {
	var emailID=document.theForm.v1;
	var studNum='';
	var surname='';
	var firname='';
	var message='';

	if (iN==19) {
		studNum=document.theForm.v3;
		surname = document.theForm.v4;
		firname = document.theForm.v5;
	} else {
		studNum=document.theForm.v4;
		surname = document.theForm.v5;
		firname = document.theForm.v6;
	}

	if (!isInteger(studNum.value) ) {
		message+="Please enter a valid Student Number\n";
		studNum.value="";
	   	studNum.focus();
    	}
	if ((emailID.value==null)||(emailID.value=="")) {
		message+="Please enter your Email Address\n";
		emailID.focus();
	} else if (echeck(emailID.value)==false) {
		message+="Please enter a valid Email Address\n";
		emailID.value="";
		emailID.focus();
	}
	if (firname.value=='') {
		message+="Please enter your First Name\n";
		firname.focus();
	}
	if (surname.value=='') {
		message+="Please enter your Family Name\n";
		surname.focus();
	}

	if (iN==24) document.theForm.v8.value=navigator.userAgent;

	if (message!='') {
		alert(message);
		return false;
	} else return true;
}