echo "<form action='aa.php?op=del&id=".$id."' method=post name=form1>";一。你action='aa.php' 右边的单引号结束过早,应该这样:action='aa.php?op=del&id=' . $id . "'"
二。参数与参数之前要用&分隔,比如:action="id=1&op=del&class=hzt"
二。参数与参数之前要用&分隔,比如:action="id=1&op=del&class=hzt"
echo "<form action='aa.php'?op=del id="$id" method=post name=form1>";
echo "<input type=hidden name=id value="$id">";
echo "<INPUT TYPE='submit' value='删除'>";
echo "</form>";
echo "</td>";
id="$id"和中间要有空格 method=post