Jquery ช่วยดูโค้ดให้ทีครับ เกี่ยวกับดึงข้อมูลจากฐานข้อมูลมาแสดงใน option

echo "
				<label>บริเวณ - ปัญหา</label>				
				<select name='area' id='id_area' class='select_text'>
					<option value='' select>== บริเวณ ==</option>";
					//วนรับค่าจากตาราง area มาแสดง
					while($resultArea = mysql_fetch_assoc($queryCountArea))
					{
						echo "<option value='".$resultArea["id_area"]."' >".$resultArea["name_area"]."</option>";
					}
				echo "
				</select>
				
				<select id='object_problem' name='object_problem' class='select_text'>
					<option value='' select disable>== ปัญหา ==</option>";
					//วนรับค่าจากตาราง mostproblems มาแสดง
					while($resultPB = mysql_fetch_assoc($queryCountPB))
					{
						echo "<option value='".$resultPB["id_mostProblems"]."' >".$resultPB["info_problems"]."</option>";
					}
			echo"		
				</select>";

function C_zone_add_operation()
	{
		if($_POST["area"] != "")
		{
			$str_area = "SELECT id_mostProblems FROM area WHERE id_area = '".$_POST["area"]."' ";
			$query_area = mysql_query($str_area) or die(mysql_error());
			$result_area = mysql_fetch_array($query_area);
			
			$str_obj_problem = "SELECT info_problems FROM mostproblems WHERE id_mostProblem = '".$result_area["id_mostProblem"]."' AND experimental_percent = '0' ";
			$query_obj_problem = mysql_query($str_obj_problem) or die(mysql_error());
			$num_obj_problem = mysql_num_rows($query_obj_problem);
			
			if($num_obj_problem > 0)
			{
				echo'
					<select name="object_problem" class="select_text">
						<option value="" select>== ปัญหา ==</option>
				';
				while($result_obj_problem = mysql_fetch_assoc($query_obj_problem))
				{
					echo'
						<option value=" '.$result_obj_problem["id_mostProblems"].' ">'.$result_obj_problem["info_problems"].'</option>
					';
				}
				echo'
					</select>
				';
			}
			break;
			
		}
}

$('#id_area').change(function(){
		$.post('checkData.php?checkData=zone_post',
			$('#id_area').val(),
			function(response){
				if(response != "")
				{
					$('#object_problem').hide();
					$('#id_area').after(function(){
						$(this).val(response);
					});
					//setTimeout("finishAjax('object_problem', '"+escape(response)+"')", 500);
				}
			},
			'html'
		);
		return false;
	});