怎么使下一个列表框自动随上一个下拉列表框的改变而改变？

仅供参考
<table align="center" width="96%" bordercolorlight="#9D0B0E" bordercolordark="#ffffff" border="1" cellpadding="2" cellspacing="0">
<form action="newslist.php?blei=<?=$blei;?>" name="form1" method="post">
<tr><td>新闻列表</td>
    <td>请选择新闻类别：</td>
<td><select name="bname" onchange="window.location=('newspub.php?blei='+this.options[this.selectedIndex].value+'')">
<option selected>请选择类别</option>
<?
include "../../inc/conn.php";
$query="select * from blei order by bid asc";
$result = @mysql_query($query);
$num = @mysql_num_rows($result);
for($i=0;$i<$num;$i++)
{
$r = @Mysql_fetch_array($result);
?>
<option value="<?=$r['bid'];?>"><?=$r['bname'];?></option>
<?
}
?>
</select>
<select name="slei">
<?
  if($blei=="")
  {
?>
<option>请选择发布区</option>
<?
  }
else
  {
$que="select * from slei where stype='$blei'";
$res = @mysql_query($que);
$renum = @Mysql_num_rows($res);
for($j=0;$j<$renum;$j++)
  {
$re = @mysql_fetch_array($res);
?>
    <option value="<?=$re['sid'];?>"><?=$re['sname'];?></option>
<?
  }}
?>
</select>
</td>
<td>
<input type="submit" name="subnews" value="提交">
</td>
</tr>
</form>
</table>

解决方案 »

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我再给你一个asp的三连动的，要自己改呀！
三级下拉框连动的数据库版三级下拉框连动
'
'数据库：
'location
'表1 loaction  所在地表
'   字段
'   loactionid
'   loactionname 名字
'表2 district  所在的地区表
'   字段
'   locationid
'    districtid
'    districtname
'表3 village  所在的县区表
'   字段
'   districtid
'   villageid
'   villagename <%Option Explicit%>
<html>
<head>
<title>List</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<%
dim conn
dim rs
dim sql
dim count
dim rs1
dim sql1
dim rs2
dim sql2
dim count2 set conn=server.createobject("adodb.connection")
conn.open"provider=sqloledb;data source=192.168.0.33;uid=sa;pwd=;database=location;"
sql = "select * from district order by locationid asc"
set rs = conn.execute(sql)
%>
<script language = "JavaScript">
var onecount;
onecount=0;
subcat = new Array();
<%
count = 0
do while not rs.eof
%>
subcat[<%=count%>] = new Array("<%= trim(rs("districtname"))%>","<%= trim(rs("locationid"))%>","<%= trim(rs("districtid"))%>");
<%
count = count + 1
rs.movenext
loop
rs.close
set rs=nothing
%>
onecount=<%=count%>; function changelocation(locationid)
{
document.myform.smalllocation.length = 0; var locationid=locationid;
var i;
document.myform.smalllocation.options[0] = new Option('==所选城市的地区==','');
for (i=0;i < onecount; i++)
{
if (subcat[i][1] == locationid)
{
document.myform.smalllocation.options[document.myform.smalllocation.length] = new Option(subcat[i][0], subcat[i][2]);
}
} }
</script>
<%sql2 = "select * from village order by districtid asc"
set rs2 = conn.execute(sql2)
%>
<script language = "JavaScript">
var onecount2;
onecount2=0;
subcat2 = new Array();
<%
count2 = 0
do while not rs2.eof
%>
subcat2[<%=count2%>] = new Array("<%= trim(rs2("villagename"))%>","<%= trim(rs2("districtid"))%>","<%= trim(rs2("villageid"))%>");
<%
count2 = count2 + 1
rs2.movenext
loop
rs2.close
set rs2=nothing
%>
onecount2=<%=count2%>; function changelocation2(villageid)
{
document.myform.village.length = 0; var villageid=villageid;
var j;
document.myform.village.options[0] = new Option('==所选地区的县区==','');
for (j=0;j < onecount2; j++)
{
if (subcat2[j][1] == villageid)
{
document.myform.village.options[document.myform.village.length] = new Option(subcat2[j][0], subcat2[j][2]);
}
} }
</script> </head>
<body>
<form name="myform" method="post">
题目：<input type="text" name="T2" size="20"> 来源：<input type="text" name="T3" size="20"> 分类：<select name="biglocation" onChange="changelocation(document.myform.biglocation.options[document.myform.biglocation.selectedIndex].value)" size="1">
<option selected>请选择你所在的省份</option>
<% sql1 = "select * from location order by locationname asc"
set rs1 = conn.Execute (sql1)
do while not rs1.eof
%>
<option value="<%=trim(rs1("locationid"))%>"><%=trim(rs1("locationname"))%></option> <%
rs1.movenext
loop
rs1.close
set rs1 = nothing
conn.Close
set conn = nothing
%>
</select><select name="smalllocation" onChange="changelocation2(document.myform.smalllocation.options[document.myform.smalllocation.selectedIndex].value)">
<option selected value="">==所有地区==</option>
</select><select name="village" size="1">
<option selected>==所有县区==</option>
</select>
关键词：<input type="text" name="T4" size="20"> 内容：<textarea rows="9" name="S1" cols="51"></textarea>
</form> </body>
</html>
思路就是国家改变时把国家这个值给一个变量并刷新页面．
使省的那个数据调条件等于那个国家的所以有省的数据．
地区同理．
这是一个跟你同理的东东你看看吧．
－－－－－－－－－－－－－－－－－－－－－－－－－－－－
     <SELECT style="FONT-SIZE: 14px;"
               onchange=OnSelectRegion(document.frmGetZM.fzm_region,document.frmGetZM.fzm_station,document.frmGetZM.Origin)
               size=1 name=fzm_region></SELECT>
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－
       <SELECT style="FONT-SIZE: 14px; width: 150px"
               onchange=OnSelectRegion(document.frmGetZM.fzm_region,document.frmGetZM.fzm_station,document.frmGetZM.Origin)
               size=1 name=fzm_region></SELECT>
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－
var region=new Array('爱立信','诺基亚');
var zm0=new Array('3310','8130','7250','8810','121210')
var zm1=new Array('3310','3311','3312','3380','3350','3370')
function InitSelect(selregion,selstation,zmfield,initarray)
{
selregion.options.length=region.length;
for (loop=0; loop < region.length; loop++)
selregion.options[loop].text=region[loop];
selregion.selectedIndex=initarray;
the_array=eval("zm"+initarray);
setOptionText(selstation,the_array,zmfield);
}
function setOptionText(selstation,the_array,zmfield)
{
selstation.options.length=the_array.length;
for (loop=0; loop < the_array.length; loop++)
selstation.options[loop].text=the_array[loop];
selstation.selectedIndex=0;
zmfield.value=selstation.options[0].text;
}
function OnSelectRegion(selregion,selstation,zmfield)
{
sel=selregion.selectedIndex;
the_array=eval("zm"+sel);
setOptionText(selstation,the_array,zmfield);
}
function OnSelectStation(selstation,zmfield)
{
sel=selstation.selectedIndex;
zmfield.value=selstation.options[sel].text;
}
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－这是我以前搞的代码自己都忘了．希望可以给你一个提示吧．最后一部分是自动生成的．可从数据中的数据自动生成你自己想想吧．呵呵．那个诺基亚可以看成是国家．型号可以看成是市．