เรื่องการดึงข้อมูลมาแก้ไขใน Dependent ListMenu [แนวคิดหน่อยครับ]

var elm = form.getElementById('select_name');

if (elm.options[x].value=="oldvalue")
{
	elm.options[x].selected = true;
	break;
}

 <?
		  include("../inc/config3.php");
		  ?>
		  		  <script language = "JavaScript">

		//**** List Amphur (Start) ***//
		function ListAmphur(SelectValue)
		{
			form1.ddlAmphur.length = 0
			form1.ddlDistrict.length = 0
			//*** Insert null Default Value ***//
			var myOption = new Option('','')  
			form1.ddlAmphur.options[form1.ddlAmphur.length]= myOption
			
			<?
			$intRows = 0;
			$strSQL = "SELECT * FROM tbl_amphur ORDER BY amphur_id ASC ";
			$objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");
			$intRows = 0;
			while($objResult = mysql_fetch_array($objQuery))
			{
			$intRows++;
			?>
				x = <?=$intRows;?>;
				mySubList = new Array();
				
				strGroup = <?=$objResult["province_id"];?>;
				strValue = "<?=$objResult["amphur_id"];?>";
				strItem = "<?=$objResult["amphur_name"];?>";
				mySubList[x,0] = strItem;
				mySubList[x,1] = strGroup;
				mySubList[x,2] = strValue;
							
				if (mySubList[x,1] == SelectValue){
					var myOption = new Option(mySubList[x,0], mySubList[x,2])  
					form1.ddlAmphur.options[form1.ddlAmphur.length]= myOption					
				}
			<?
			}
			?>																	
		}
		//**** List Amphur (End) ***//
		
				//**** List District (Start) ***//
		function ListDistrict(SelectValue)
		{
			form1.ddlDistrict.length = 0
			//*** Insert null Default Value ***//
			var myOption = new Option('','')  
			form1.ddlDistrict.options[form1.ddlDistrict.length]= myOption
			
			<?
			$intRows = 0;
			$strSQL = "SELECT * FROM tbl_district ORDER BY district_id ASC ";
			$objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");
			$intRows = 0;
			while($objResult = mysql_fetch_array($objQuery))
			{
			$intRows++;
			?>
				x = <?=$intRows;?>;
				mySubList = new Array();
				
				strGroup = <?=$objResult["amphur_id"];?>;
				strValue = "<?=$objResult["district_id"];?>";
				strItem = "<?=$objResult["district_name"];?>";
				mySubList[x,0] = strItem;
				mySubList[x,1] = strGroup;
				mySubList[x,2] = strValue;
							
				if (mySubList[x,1] == SelectValue){
					var myOption = new Option(mySubList[x,0], mySubList[x,2])  
					form1.ddlDistrict.options[form1.ddlDistrict.length]= myOption					
				}
			<?
			}
			?>																	
		}
		//**** List District (End) ***//

</script>
            <td height="23"><span style="color: #0000FF">จังหวัด :
                <label>
                <select name="ddlProvince" id="ddlProvince" onChange = "ListAmphur(this.value)">
                  <option value="-">ระบุจังหวัด</option>
                  <?
				$strSQL = "SELECT * FROM tbl_province ORDER BY province_name ASC ";
				$objQuery = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");
				while($objResult = mysql_fetch_array($objQuery))
				{
				?>
                  <option value="<?=$objResult["province_id"];?>" <? if($row[provinceID]==$objResult["province_id"]){echo"selected";}?>>
                  <?=$objResult["province_name"];?>
                  </option>
                  <?
				}
				?>
                </select>
                </label>
            </span></td>
            <td><span style="color: #0000FF">อำเภอ : 
                <label>
                <select name="ddlAmphur" id="ddlAmphur"  onChange = "ListDistrict(this.value)" >
                  <option selected value="-">ระบุอำเภอ</option>
				       <?
				$strSQL = "SELECT * FROM tbl_amphur ORDER BY amphur_name ASC ";
				$objQuery2 = mysql_query($strSQL) or die ("Error Query [".$strSQL."]");
				while($objResult2= mysql_fetch_array($objQuery2))
				{
				?>
                  <option value="<?=$objResult2["amphur_id"];?>" <? if($row[amphurID]==$objResult2["amphur_id"]){echo"selected";}?>>
                  <?=$objResult2["amphur_name"];?>
                  </option>
                  <?
				}
				?>
                  </select>
                </label>
            </span></td>
            <td><span style="color: #0000FF">ตำบล : 
                <label>
                <select name="ddlDistrict" id="ddlDistrict" >
                  <option value="-">ระบุตำบล</option>
                  </select>
                </label>
            </span></td>
<?
	mysql_close($objConnect);
?>