<script type="text/javascript" src="./js/jquery-1.2.2.pack.js" ></script>
function judge() //判断idstream_number里的值。然后根据这个值设置div里的内容是否显示。
{
var stream_number_value=document.getElementById("stream_number").value;
if(stream_number_value==0)
{
$('#stream_judge2').css("display","none");
$('#stream_judge3').css("display","none");
$('#stream_judge4').css("display","none");
}
if(stream_number_value==1)
{
$('#stream_judge2').css("display","");
$('#stream_judge3').css("display","none");
$('#stream_judge4').css("display","none");
}
}
<td>
<select name = "stream_number" id="stream_number" style="width:100" onchange="judge()">
<option value = "0" selected="">1</option>
<option value = "1">2</option>
<option value = "2">3</option>
<option value = "3">4</option>
</select>
//被设置的div
<div id="stream_judge2" name="stream_judge2" style="display:none">
<fieldset>
</fieldset>
</div>