看看下面这个对你有帮助没有:
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>无标题文档</title>
<script language="JavaScript" type="text/JavaScript">
function bubuycctv()
{
var l;
for (l=document.form1.bubuy.options.length-1;l>=0;l--)
if(document.form1.bubuy.options[l].value==document.form1.cctv.value){
document.form1.bubuy.options[l].selected=true;
break;
}
}
</script></head><body>
<form name="form1">
<input name="cctv" type="text" value="bubuy3" onBlur="bubuycctv();">
<select name="bubuy" >
<option value="bubuy1">bubuy1</option>
<option value="bubuy2">bubuy2</option>
<option value="bubuy3">bubuy3</option>
</select>
</form>
</body>
</html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>无标题文档</title>
<script language="JavaScript" type="text/JavaScript">
function bubuycctv()
{
var l;
for (l=document.form1.bubuy.options.length-1;l>=0;l--)
if(document.form1.bubuy.options[l].value==document.form1.cctv.value){
document.form1.bubuy.options[l].selected=true;
break;
}
}
</script></head><body>
<form name="form1">
<input name="cctv" type="text" value="bubuy3" onBlur="bubuycctv();">
<select name="bubuy" >
<option value="bubuy1">bubuy1</option>
<option value="bubuy2">bubuy2</option>
<option value="bubuy3">bubuy3</option>
</select>
</form>
</body>
</html>
<HEAD><script language=javascript>
<!-- // hide script from old browsers// JavaScript Code created by:
// Menu Master JavaScript Coder
// written by:
// Pat Friedl of Nebulus Designs
// http://nebulus.org
// This script is (C) 1998
// and may not be re-distributed without permission
// for questions, email me at [email protected] goThere() {
var list = document.menumaster.navchoices;
if(location = list.options[list.selectedIndex].value != "") {
parent.main.document.location = list.options[list.selectedIndex].value;
}
}// end hiding -->
</script><TITLE>FREE TEMPLATE</TITLE>
<META name="description" content="">
<META name="keywords" content="">
</HEAD>
<BODY>
<TABLE ALIGN=center height="83" width="675">
<TR><TD height="79" width="219">
<form name="menumaster">
<select name="navchoices" onChange="goThere()">
<option value="" selected>请选择你需要的版块!</option>
<option value="版块名">菜单名</option>
<option value="版块名">菜单名</option>
<option value="版块名">菜单名</option>
<option value="版块名">菜单名</option>
<option value="版块名">菜单名</option>
<option value="版块名">菜单名</option>
<option value="版块名">菜单名</option>
<option value="版块名">菜单名</option>
<option value="版块名">菜单名</option>
<option value="版块名">菜单名</option>
</select>
</form>
</TD></TR>
</TABLE></BODY>
</HTML>
看看有没有用喽!!我也不是太熟悉