请问：这两句PHP语句有何问题？$myrow = mysql_fetch_array($rs)

<?
$rs=mysql_query("SELECT * FROM dyxx WHERE zhushi='tzsc_vip' order by rq desc limit $offset,$pagesize");
$myrow = mysql_fetch_array($rs);
while ($myrow = mysql_fetch_array($rs))
{
echo "
<tr>
<td width='450' height='25'><font color='#EF8818'>※</font><a class='wb' href='nr.php?action=bt&id=".$id."'>".$myrow['title']."</a></td>
<td width='120' height='25' align='center'>".$myrow['rq']."</td>
</tr>";
}
?>

返回说这两句有问题：
Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in F:\myweb\tzsc.php on line 23
Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in F:\myweb\tzsc.php on line 24
即这两句：
$myrow = mysql_fetch_array($rs);
while ($myrow = mysql_fetch_array($rs))

注：zhushi字段是我后来在phpmyadmin中加的，其内容tzsc_vip也是直接在phpmyadmin中原来的信息后加入的，这样应该也是可以的吧？跟这会有关系吗？我觉得可能是语法上的问题，但不知在哪？请赐教！非常感谢！