<form action="" method="post" onsubmit="this.action=this.hi.value+'.php');">
<select name=hi>
<option value=1>net</option>
<option value=2>hello</option>
</select><input type=submit></from>
<select name=hi>
<option value=1>net</option>
<option value=2>hello</option>
</select><input type=submit></from>
<select name=hi onchange="send()">
<option value=1>net<option>
<option value=2>hello</option>
</select><input type=submit></from><script>
function send(){
if(document.forms[0].hi.value=="1"){
document.forms[0].action = "2.php"
document.forms[0].submit
}
if(document.forms[0].hi.value=="2"){
document.forms[0].action = "3.php"
document.forms[0].submit
} }
</script>
<select name=hi onclick="myclick();">
<option value=1>net<option>
<option value=2>hello</option>
</select><input type=submit></from>
<script language="javascript">
<!--
function myclick()
{
if(document.myform.sun1.selectedIndex==0) //net
{
// 2.php
}
else //hello
{
//3.php
}
//php我不会,你自己写提交的代码
}
// -->
</script>