/*
 * JavaScript email validation script.
 */

function ValidateForm(emailID){
/****************************************************************/
/* This function takes one argument, a string entered in a text */
/* box. It then checks to see if the string is a valid email    */
/* address. If not valid an alert is displayed.                 */
/****************************************************************/
		
	if ((emailID.value==null)||(emailID.value=="")){
		doMessage();
		return false
	}
	if (echeck(emailID.value)==false){
		emailID.value=""
		return false
	}
	return true
 }


function doMessage() {
window.alert('Please enter a valid E-mail address!');
}

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){
	   doMessage();
	   return false
	}

	if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
	   doMessage();
	   return false
	}

	if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
	    doMessage();
	    return false
	}

	 if (str.indexOf(at,(lat+1))!=-1){
	    doMessage();
	    return false
	 }

	 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
	    doMessage();
	    return false
	 }

	 if (str.indexOf(dot,(lat+2))==-1){
	    doMessage();
	    return false
	 }
		
	 if (str.indexOf(" ")!=-1){
	    doMessage();
	    return false
	 }

	 return true					
	}