function verifyRequired() {
  if (document.icpsignup["fields_email"].value == "") {
    document.icpsignup["fields_email"].focus();
    alert("The Email field is required.");
    return false;
  }
  
  if (document.icpsignup["fields_zip"].value == "") {
    document.icpsignup["fields_zip"].focus();
    alert("The Zip field is required.");
    return false;
  }

  if (
      !document.icpsignup["listid:9858293"].checked &&
      !document.icpsignup["listid:9858287"].checked &&
      !document.icpsignup["listid:9857268"].checked &&
      !document.icpsignup["listid:9857007"].checked &&
      !document.icpsignup["listid:9857280"].checked &&
      true)  {
    alert("The Lists field is required.");
    return false;
  }

  return true;
}