<head>
<meta http-equiv="Content-Type" ontent="text/html; charset=gb2312" />
<title>表单元素[select下拉列表]制作二级联动菜单</title>
<?php
$link = mysql_connect('localhost','root','root') or die( mysql_error());
mysql_select_db('cshouse',$link) or die('db error');
mysql_query("set Names'gbk'");
/*$sql = "Select * from zgy_classplace where upid=0 order by id asc";
$result = mysql_query( $sql );
$i =1;
$count = mysql_num_rows( $result );
$b=',';
while( $rs = mysql_fetch_array( $result ) )
{
if( $i==$count ){ $b =''; }
echo " new Array("$rs[id]","$rs[cntitle]")$b nt";
$i++;
}
echo ");";
*/
?>
<script language="javascript">
//下面函数是演示二，联动菜单的处理代码
function makeplace_a(x){
var form2=document.wane_search.one.options.length;//这句解释同上
var wane_searchl=new Array(form2)//新建一个数组，项数为第一个下拉列表的项数
for(i=0;i<form2;i++)//循环第一个下拉列表的项数那么多次
wane_searchl[i]=new Array();//子循环
//下面是给每个循环赋值
var place_a=document.wane_search.place_a;//方便引用
<?php
$sql = "Select * from zgy_classplace where upid=0 ";
$result = mysql_query( $sql );
$j =1;
while( $rs = mysql_fetch_array( $result ) )
{
$sql = mysql_query("Select * from zgy_classplace where upid='$rs[id]' and upid<>0") ;
$i =0;
while( $p =mysql_fetch_array( $sql ) ) {
echo "wane_searchl[$j][$i] = new Option("$p[cntitle]","$p[id]"); nt";
$i++;
}
$j++;
}
?>
for(m=place_a.options.length-1;m>0;m--)
//这个要看清楚,因为要重新填充下拉列表的话必须先清除里面原有的项,清除和增加当然是有区别的了,所以用递减
place_a.options[m]=null;//将该项设置为空,也就等于清除了
for(j=0;j<wane_searchl[x].length;j++){//这个循环是填充下拉列表
place_a.options[j]=new Option(wane_searchl[x][j].text,wane_searchl[x][j].value)
//注意上面这据,列表的当前项等于 新项(数组对象的x,j项的文本为文本，)
}
place_a.options[0].selected=true;//设置被选中的初始值
}
</script>
</head>
<body>
<form id="form20" name="wane_search" method="post" action="">
<select name="one" size="1" onchange="makeplace_a(options.selectedIndex)">
<option value="">---请选择省份---</option>
<?php
$sql_pr = "Select * from zgy_classplace where upid=0";
$result_pr = mysql_query( $sql_pr );
while( $rs_pr = mysql_fetch_array( $result_pr ) )
{
echo "<option value=$rs_pr[id]>$rs_pr[cntitle]</option> nt";
}
?>
</select>
<select name="place_a">
<option value="">---请选择城市---</option>
</select>
<label>
<input type="submit" name="Submit" value="提交">
</label>
</form>
<?php
if($_POST)
{
print_r($_POST);
}
?>
</body>
</html>