ถามเรื่อง list/menu 2 ชั้นหน่อยครับ คือผมทำ โมดูล add ข่าว โดยจะมีการใช้ list/menu 2 ชั้น แปรผันตามกัน

<script type="text/javascript">
$(function(){
	$("select#cat").change(function(){
		var datalist2 = $.ajax({	
			  url: "getsubcate.php", 
			  data:"cat="+$(this).val(), 
			  async: false
		}).responseText;		
		$("select#sub").html(datalist2); 
		
	});
});
</script>

$cid = $_REQUEST["cid"];
$sid = $_REQUEST["sid"];

// ทฟรื
<select name="cat" id="cat" style="width:100px;">
    <option value="">Select</option>
	<?
		$sqlc = "SELECT cat_name, cat_id FROM cat_tbl ORDER BY cat_id";
		$resultc = mysql_query($sqlc);
		while($rsc = mysql_fetch_array($resultc))
		{ 
	?>
                    <option value="<?=$rsc[cat_id]?>" <? if($cid==$rsc[cat_id]){echo "selected";} ?>><?=$rsc[cat_name]?></option>
	<?
		 }
	?>               
                     
</select>

// sub

<select name="sub" id="sub">
     <option value="">Select</option>
</select>

header("Content-type: application/xhtml+xml; charset=utf-8"); 
header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1

include_once("../includes/config.inc.php"); 
if(isset($_GET['cat']) && $_GET['cat']!="")
{
 
    echo "<option value=''>Select</option>";
 
    $sql = "SELECT sub_id, sub_name FROM catsub_tbl WHERE cat_id=".$_GET['cat']." ";
	$result = mysql_query($sql);
	while($rs = mysql_fetch_array($result))
    
	{ 
  
       echo "<option value='$rs[sub_id]'>$rs[sub_name]</option>";
   
    } 

}else{ 

  echo "<option value=''>select</option>";

}