in the frame based menu! why the sub menu cant be drag down?

[lauchunhui]

i refer the

http://milonic.com/menu/frames/

in the frame_body.htm file, i add an inframe

script language=JavaScript src="mmenu.js" type=text/javascript></script>

<script language=javascript>
if(ns4)_d.captureEvents(Event.MOUSEMOVE)
_d.onmouseup=closeallmenus
</script>

</body>
<iframe src="home.jsp" height="500" width="100%" ><i/frame>***
</html>

home.jsp is a file to show contents only !!

i can drag down the sub menu before click the sub menu !!!

later, i click the sub menu, and the page link to the content correctly , but i cant drag down the sub menu ???

any advice ???

[lauchunhui]

somebody help me !!!??!!

i hope someone can give me some ideal or advices !!!