function ValidateForm(f) {
	if (!isEmail(f.EmailAddress.value)) 
	{
	alert("Please enter a valid email address");
	return false;
	
	}
	
}

function isEmail(v) {
	at=v.indexOf('@');
	dot=v.lastIndexOf('.');
	end=v.length;
	subone=v.substring(at+1,dot);
	domainbeforedot=subone.length;
	subtwo=v.substring(dot+1,end);
	domainafterdot=subtwo.length;
   	if (v.indexOf ('@',0) == -1 || v.indexOf ('.',0) == -1  || domainbeforedot < 1 || domainafterdot < 2 ) {
      		return false;
	}
   	else { 
   		return true; 
   	}
}