跳出输入框
<script language="javascript">
function $(obj){return document.getElementById(obj);}
function show(objid) {$(objid).style.display='inline';}
function hidden(objid) {$(objid).style.display='none';}
function doit(){
var sel_val=$('sel').value;
if (sel_val=='') {hidden('a1');hidden('a2');}
if (sel_val==) {hidden('a1');hidden('a2');}
if (sel_val==) {show('a1');hidden('a2');}
if (sel_val==) {show('a2');hidden('a1');}
}
</script>
</head> <body>
<select name="sel" id="sel" onchange="javascript:doit();">
<option selected="selected">请选择</option>
<option value="">不要输入框</option>
<option value="">输入框1</option>
<option value="">输入框2</option>
</select> <input value="输入框1" type="text" name="a1" id="a1" style="display:none;" />
<input value="输入框2" type="text" name="a2" id="a2" style="display:none;" />
<br />
<br />
</body>
跳出选择框
<html>
<head>
<script type="text/javascript">
function change(){
var a=document.getElementById('aa').value;
if(a== || a==)
{
document.getElementById('bb').style="display:none;"
}
if(a== || a==)
{
document.getElementById('bb').style="display:block;"
}
}
</script>
</head>
<body>
<select id="aa" onchange="change()">
<option value="">aa</option>
<option value="">bb</option>
<option value="">cc</option>
<option value="">dd</option>
</select>
</br>
<select id="bb" style="display:none;">
<option value=""></option>
<option value=""></option>
<option value=""></option>
<option value=""></option>
</select>
</body>
</html>