function validateLeftNavLocatorForm(){
   var IsError = false;
   
   if (document.getElementById("LeftNavPostalCode").value == ""){
      alert("You must enter your zip code.");
      document.getElementById("LeftNavPostalCode").focus();
      IsError = true;
   }
   
   if (!IsError){
      document.getElementById("LeftNavLocatorForm").submit();
   }
}