如何用下拉框实现这样的功能，请教！，在线等！

Question

<select onchange="test()">
<options value="1.htm">aaa
<options value="2.htm">bbb
</select>
<iframe name="frm" src="1.htm"></iframe><script>
function test(){frm..location.href=event.srcElement.options[event.srcElement.selectedIndex].value;}
</script>

Answer 1

<select onchange="frm.locatin.href=this.value">
<options value="1.htm">aaa
<options value="2.htm">bbb
</select>

Answer 2

ordemo.htm<frameset rows="30%,*" id="baobao">
  <frame src="top.htm" name="topFrame">
  <frame src="bottom.htm" name="bottomFrame">
</frameset>top.htm<select onchange="window.open(this.value,'bottomFrame','')">
<option value="1.htm">item1
<option value="2.htm">item2
</select>