//-------------------------------------------------------------------------------------------------------------------------------
// Name : mailcheck();
// Purpose : To check weather entered email address is valid or not
//-------------------------------------------------------------------------------------------------------------------------------
function mailcheck(str) 
{
		var at="@";
		var dot=".";
		var lat=str.indexOf(at);
		var lstr=str.length;
		var ldot=str.indexOf(dot);
		var strval = lstr-1;
	
		if (str.indexOf(at)==-1)
		{
		   alert("Invalid E-mail ID");
		   return false;
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr)
		{
		   alert("Invalid E-mail ID");
		   return false;
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr)
		{
		    alert("Invalid E-mail ID");
		    return false;
		}

		 if (str.indexOf(at,(lat+2))!=-1)
		 {
		    alert("Invalid E-mail ID");
		    return false;
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot)
		 {
		    alert("Invalid E-mail ID");
		    return false;
		 }

		 if (str.indexOf(dot,(lat+2))==-1)
		 {
		    alert("Invalid E-mail ID");
		    return false;
		 }
		
		 if (str.indexOf(" ")!=-1)
		 {
		    alert("Invalid E-mail ID");
		    return false;
		 }
		
		 if (strval == ldot)
		 {
			
			alert("Invalid E-mail ID");
			return false;
		 }	
 		 return true;					
}
	function validate(frm)
	{
		with(frm)
		{
			if(txtZip3.value == '')
			{
				alert("Please Enter Name");
				txtZip3.focus();
				return false;
			}
			if(txtZip4.value == '')
			{
				alert("Please Enter Email");
				txtZip4.focus();
				return false;
			}
			else if(mailcheck(txtZip4.value)==false)
			{
				txtZip4.focus();
				return false;
			}
			if(comments.value == '')
			{
				alert("Please Enter Comments");
				comments.focus();
				return false;
			}
		}
		return true;	
	}