連動的下拉式選單

<form name="myForm" action="" method="post"> 科目：<select name="kind" onchange="Buildkey(this.selectedIndex);"> <option value="3" selected>6252</option> <option value="8">6251</option> <option value="12">6253</option> <option value="14">6254</option> <option value="16">6256-501</option></select> <select name="kind2"> <option value="11" selected>租金</option> </select></form> <script language="JavaScript"> key=new Array(); key[0]=new Array(); key[0][0]=new Option("租金","11"); key[1]=new Array(); key[1][0]=new Option("薪資","10"); key[2]=new Array(); key[2][0]=new Option("文具用品","13"); key[3]=new Array(); key[3][0]=new Option("差旅費","15"); key[4]=new Array(); key[4][0]=new Option("電話費","17"); key[5]=new Array(); key[5][0]=new Option("網路諮詢","19"); function Buildkey(num) { document.myForm.kind2.selectedIndex=0; for(ctr=0;ctr<key[num].length;ctr++){ document.myForm.kind2.options[ctr]=new Option(key[num][ctr].text,key[num][ctr].value); } document.myForm.kind2.length=key[num].length; } </script> key[][]=new Option([show],[value]); 相等於 <option value="[value]">[show]</option>