ดึงข้อมูลจาก sql มาใส่ใน select menu ข้อมูลไม่มาค่ะ

<select id="select" name="payCost" onChange="" >
                            <?php 
 
       $str_server = "localhost";
       $str_username = "";
       $str_password = "";
       $str_dbname = "";
       $obj_con = mysql_connect($str_server,$str_username,$str_password);
       mysql_select_db($str_dbname,$obj_con);
       mysql_query("SET NAMES UTF8");
 
$query_list=mysql_query("Select payCost From payTeach WHERE status='0'");?>
                            <option>-เลือกค่าตอบแทน-</option>
                            <?
while($sl < mysql_num_rows($query_list)){
$arrL= mysql_fetch_array($query_list);
?>                           
                            <option value="<?php echo $arrL['payCost'];?>"><?php echo $arrL['payCost'];?></option>
                            <?php
$sl++;
}
mysql_close($obj_con)
?>
                          </select>