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 register_newsletter() {
    var AJAX  = new XMLHttpRequest();  
    var email = document.getElementById('ea');

    if ( (email.value==null)||(email.value=="")||(echeck(email.value)==false) ){
        alert("Please enter a valid email address")
        return false
    }
    else{
	   AJAX.onreadystatechange = function() { 
            if (AJAX.readyState==4){
                document.getElementById('newsletter_message').innerHTML = '<strong>Thank you for registering to our newsletter</strong>';
				document.getElementById('ea').value = '';
            }
	   }
				  
       AJAX.open("GET","newsletter.php?email="+email.value,true);
       AJAX.send(null);
    }
}