function valid_email(str) {
		var error_msg = 'Please enter a valid email address';
		var at="@"
		var dot="."
		var lat=str.indexOf(at)
		var lstr=str.length
		var ldot=str.indexOf(dot)
		if ((str==null)||(str==""))
		{
		   alert(error_msg)
		   return false
		}
		if (str.indexOf(at)==-1){
		   alert(error_msg)
		   return false
		}

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

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

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

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

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

 		 return true					
		}
	
		function validate() {
			var fname = document.form.first_name;
			var lname = document.form.last_name;
			var emailaddress = document.form.email_address;

			
			if (fname.value == '') { 
				alert('Please enter your First name.');
				fname.focus();
				return false; 
			}
			if (lname.value == '') { 
				alert('Please enter your Last name.');
				lname.focus();
				return false; 
			}			
			if (valid_email(emailaddress.value)==false){
				emailaddress.focus();
				return false;
			}
			
			return true;
		}