function validate_form(form)
{
	if(form.trans) // if advanced search form
	{
		var zip = form.mmZip;
	}
	else
	{
		var zip = form.tZip;
	}

	if(!validate_zip(zip))
	{
		alert('Please enter a 5 digit zip code.');	
	 	zip.style.borderColor="red";
		return false;
	}

	return true;
}


function validate_zip(zip)
{
	if(isNaN(zip.value)) return false;

	if(zip.value.length !== 5) return false;

	return true;
}