<script type="text/javascript">

//当第一级选项发生变化的时候跳转

function jump() {

location.href='?firstid='+document.getElementById('first').value;

}

</script>

<?php

//连接数据库

@mysql_connect('localhost','root','');

mysql_select_db('test');

mysql_query('set names utf8');

$firstid=isset($_GET['firstid'])?$_GET['firstid']:'';	//获取提交的firstid

?>

<!--获取第一级-->

<select id='first' onchange='jump()'>

<option value="">---请选择---</option>

<?php

$sql='select * from shoplist where parentid=0';

$rs=mysql_query($sql);

while($rows=mysql_fetch_assoc($rs)):

?>

<option value="<?php echo $rows['id']?>" <?php echo $rows['id']==$firstid?'selected':''?>><?php echo $rows['name']?></option>

<?php

endwhile;

?>

</select>

<!--获取第二级-->

<select id='second'>

<option value="">---请选择---</option>

<?php

$sql="select * from shoplist where parentid=$firstid";

$rs=mysql_query($sql);

while($rows=mysql_fetch_assoc($rs)):

?>

<option value="<?php echo $rows['id']?>"><?php echo $rows['name']?></option>

<?php endwhile;	?>

</select>