function searchbox_check() {
if ((document.searchbox_form.searchbox.value == "") || (document.searchbox_form.searchbox.value == " ") || (document.searchbox_form.searchbox.value == "  ") || (document.searchbox_form.searchbox.value == "   ")) {
alert("โปรดใส่คำค้นในช่องค้นหา!");
return false;
	}
}