function SortStateSelect() 
{
	var text_enter_zipcode = "Enter a zipcode";
	var f = document.frmDirectory;
	if (f.State.value == 'zip')
	{
		var enterZipcode   = prompt(text_enter_zipcode, "");
    		f.SortFromZipcode.value+=enterZipcode;
	}
	{
		f.submit();			
	}
}