<body onLoad="s()">
<form id="form1" name="form1" method="post" action=""><select name="select" id="select" onchange="s()">
<option value="1">1</option>
<option value="2" selected="selected">2</option>
<option value="3">3</option>
</select>
<input type="text" name="hd" id="hd"/></form>
<script>
function s(){
document.getElementById('hd').value = document.getElementById('select').value;}
</script >
<form id="form1" name="form1" method="post" action=""><select name="select" id="select" onchange="s()">
<option value="1">1</option>
<option value="2" selected="selected">2</option>
<option value="3">3</option>
</select>
<input type="text" name="hd" id="hd"/></form>
<script>
function s(){
document.getElementById('hd').value = document.getElementById('select').value;}
</script >
<input type="hidden" name="x">
<select name="y" onchange="">
<option value="a">hello</option>
</select>
</form>
<script language="javascript">
function get_value()
{
document.form1.x.value = document.form1.y.options[form1.y.selectIndex].value;
}
</script>大概是这样,可能有个别函数有问题,LZ查看一下MSDN吧~
<script>
documnet.getElementById("objhid").value = documnet.getElementById("objslt").[documnet.getElementById("objslt").selectIndex].value;
<script>It is equal to onload()