function ValidateEmail(email) {
  if (email=="") {
    alert ("Email is required!");
    return false; 
  }

  re = /^[\w-\.]+@([\w-]+\.)+([a-z]{2,4})$/i ;

  if(re.test(email)) {
    return true;
  } else {
    alert("Invalid E-mail. Please re-enter");
    return false;
  }

}