下拉框连动的小例子（.htm版）

< html >
< head >
< title >List< /title >
< meta http-equiv="Content-Type" content="text/html; charset=gb2312" >
< script LANGUAGE="javascript" >
< !--
var onecount;
onecount=0;
    
subcat = new Array();
subcat[0] = new Array("徐汇区","01","001");
subcat[1] = new Array("嘉定区","01","002");
subcat[2] = new Array("黄浦区","01","003");
subcat[3] = new Array("南昌市","02","004");
subcat[4] = new Array("九江市","02","005");
subcat[5] = new Array("上饶市","02","006");

onecount=6;

function changelocation(locationid)
    {
    document.myform.smalllocation.length = 0; 

    var locationid=locationid;
    var i;
    document.myform.smalllocation.options[0] = new Option('====所有地区====','');
    for (i=0;i <  onecount; i++)
        {
            if (subcat[i][1] == locationid)
            { 
            document.myform.smalllocation.options[document.myform.smalllocation.length]
 = new Option(subcat[i][0], subcat[i][2]);
            }        
        }
        
    }    

//-- >
< /script >
< /head >
< body >
< form name="myform" method="post" >
    < select name="biglocation" 
onChange="changelocation(document.myform.biglocation.options[document.myform.biglocation.selectedIndex].value)" >
        < option value="01" selected >上海< /option >
        < option value="02" >江西< /option >
    < /select >
    < select name="smalllocation" > 
        < option selected value="" >==所有地区==< /option >
    < /select >
< /form >
< script LANGUAGE="javascript" > 
< !-- 
    changelocation(document.myform.biglocation.options[document.myform.biglocation.selectedIndex].value); 
//-- > 
< /script >
< /body >
< /html >