function nletterForm(){

var emailID=document.nletterfrm.textfield
	
if (document.nletterfrm.textfield.value < 1 || document.nletterfrm.textfield.value == 'Enter e-mail address')
	{
		alert("Please Enter your Email Address")
		return false;
	}
if (echeck(emailID.value)==false)
	{
		emailID.value=""
		emailID.focus()
		return false;
	}
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){
		   alert("Please Enter a Correct Email Address")
		   return false
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   alert("Please Enter a Correct Email Address")
		   return false
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    alert("Please Enter a Correct Email Address")
		    return false
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    alert("Please Enter a Correct Email Address")
		    return false
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    alert("Please Enter a Correct Email Address")
		    return false
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    alert("Please Enter a Correct Email Address")
		    return false
		 }
		
		 if (str.indexOf(" ")!=-1){
		    alert("Please Enter a Correct Email Address")
		    return false
		 }

 		 return true;				
	}
}