<select id="select1" onchange="liu()"><opion>tt</opion></select>
<script>
function liu(){
var o = document.getElementById("select1");
if(o.selected.value==tt){
window.location.href="xxx.htm";
}
}
<script>
function liu(){
var o = document.getElementById("select1");
if(o.selected.value==tt){
window.location.href="xxx.htm";
}
}
<option value="http://www.163.com">
<option value="http://www.sina.com.cn">
</select>
<input type=button onclick="window.location.href=document.all.sel.value;">
<opion>tt</opion>
<opion>tt</opion>
<opion>tt</opion>
<opion>tt</opion>
</select>
<script>
function liu(){
var o = document.getElementById("select1");
if(o.selected.value==tt){
window.location.href="http://www.csdn.net";
}
}
</script>这样吗,不行呀