function validate(myForm)
{
   validExp = /^(\d{5})(\-\d{4})?$/;
   
   if (myForm.zip_code.value.search(validExp) == -1)
   {
      alert('Please enter a valid zip code');
      return false;
   }
}

function validate2(myForm)
{
   if (myForm.state.selectedIndex == 0)
   {
      alert('Please select a state.');
      return false;
   }
}