if (!(BrowserDetect.browser == "Explorer" && BrowserDetect.version < 6)) {
  Event.observe(window, "load", function() {
       
  });
}
function validate_fields(){
  //validate zip code
  var is_valid = true;
  
  if( !$("has_existing_carrier_1").checked && !$("has_existing_carrier_0").checked){
    is_valid = false;
    alert("Please indicate your current coverage status.");       
  }
  if(is_valid){
    if(  !/^\d{5}$/.test($F("address1_zip"))  ){
      is_valid = false;
      alert("Please enter a valid zip code.");   
    }
  }
  
  return is_valid;
}