// JavaScript to check for valid email address.

//This function thus simply makes sure the email address has one (@) and atleast one (.). 
//It also makes sure that there are no spaces, extra '@'s or a (.) just before or after the @. 
//It also makes sure that there is atleast one (.) after the @.
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 valid email address.")
		   return false
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   alert("Please enter a valid email address.")
		   return false
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    alert("Please enter a valid email address.")
		    return false
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    alert("Please enter a valid email address.")
		    return false
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    alert("Please enter a valid email address.")
		    return false
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    alert("Please enter a valid email address.")
		    return false
		 }
		
		 if (str.indexOf(" ")!=-1){
		    alert("Please enter a valid email address.")
		    return false
		 }

 		 return true					
	}

//This function is used to make sure that the email field is not blank and that 
//there is a valid email address on form submission.
function ValidateForm(){
	var emailID=document.maillist.email
	
	if ((emailID.value==null)||(emailID.value=="")){
		alert("Please enter a valid email address.")
		emailID.focus()
		return false
	}
	if (echeck(emailID.value)==false){
		emailID.value=""
		emailID.focus()
		return false
	}
	return true
 }