asp只能在client端处理,对<select>加上onchange事件处理
<script lanauage="javascript">
function changeselect()
{
if (FORM1.intericon.options[FORM1.intericon.selectedIndex].value=="")
FORM1.edit.style.visibility="visible";
else
FORM1.edit.style.visibility="hidden";
}
</script>
<Form name=FORM1>
<select style="WIDTH: 100%" name="intericon" onchange="javascript:changeselect()">
<option value='广州' selected>广州</option>;
<option value='将门' >江门</option>;
<option value="" >其他城市</option>
</select>
<input name=edit id=edit value="" style="visibility:hidden">
</form>