这是一个用js写的菜单，现在问题是他菜单出现是想上我现在想让它向下怎么改啊，大家帮忙啊，结帖马上散分
<script type= "text/javascript ">
var menu1=new Array()
menu1[0]= ' <a href= "AddUser.aspx " target= "main "> 添加用户 </a> '
menu1[1]= ' <a href= "UserRole.aspx " target= "main "> 用户权限 </a> '
menu1[2]= ' <a href= "EditUser.aspx " target= "main "> 修改用户 </a> '
menu1[3]= ' <a href= "AddRole.aspx " target= "main "> 添加角色 </a> '
menu1[4]= ' <a href= "EditRole.aspx " target= "main "> 修改角色 </a> '
menu1[5]= ' <a href= "Role1.aspx " target= "main "> 角色权限 </a> '
//Contents for menu 2, and so on
var menu2=new Array()
menu2[0]= ' <a href= "Dept.aspx " target= "main "> 专业管理 </a> '
menu2[1]= ' <a href= "SystemManage.aspx " target= "main "> 机组管理 </a> '
menu2[2]= ' <a href= "Device.aspx " target= "main "> 设备管理 </a> '
menu2[3]= ' <a href= "GLPoint.aspx " target= "main "> 测点管理 </a> '
menu2[4]= ' <a href= "Style.aspx " target= "main "> 类型管理 </a> '
menu2[5]= ' <a href= "ReData.aspx " target= "main "> 数据备份 </a> '
menu2[6]= ' <a href= "ResData.aspx " target= "main "> 数据还原 </a> '

var menu3=new Array()
menu3[0]= ' <a href= "Plan.aspx " target= "main "> 添加计划 </a> '
menu3[1]= ' <a href= "PlanUse.aspx " target= "main "> 计划分配 </a> '
menu3[2]= ' <a href= "Plans.aspx " target= "main "> 计划查看 </a> '

var menu4=new Array()
menu4[0]= ' <a href= "DataSelect.aspx " target= "main "> 结果查询 </a> '
menu4[1]= ' <a href= "assay.aspx " target= "main "> 定制曲线 </a> '
var menuwidth= '165px ' //default menu width
var menubgcolor= 'lightyellow ' //menu bgcolor
var disappeardelay=250 //menu disappear speed onMouseout (in miliseconds)
var hidemenu_onclick= "yes " //hide menu when user clicks within menu?

/////No further editting needed

var ie4=document.all
var ns6=document.getElementById&&!document.all

if (ie4||ns6)
document.write( ' <div id= "dropmenudiv " style= "visibility:hidden;width: '+menuwidth+ ';background-color: '+menubgcolor+ ' " onMouseover= "clearhidemenu() " onMouseout= "dynamichide(event) "> </div> ')

function getposOffset(what, offsettype){
var totaloffset=(offsettype== "left ")? what.offsetLeft : what.offsetTop;
var parentEl=what.offsetParent;
while (parentEl!=null){
totaloffset=(offsettype== "left ")? totaloffset+parentEl.offsetLeft : totaloffset+parentEl.offsetTop;
parentEl=parentEl.offsetParent;

}
return totaloffset;
}


function showhide(obj, e, visible, hidden, menuwidth){
if (ie4||ns6)
dropmenuobj.style.left=dropmenuobj.style.top= "-500px "
if (menuwidth!= " "){
dropmenuobj.widthobj=dropmenuobj.style
dropmenuobj.widthobj.width=menuwidth
}
if (e.type== "click " && obj.visibility==hidden || e.type== "mouseover ")
obj.visibility=visible
else if (e.type== "click ")
obj.visibility=hidden
}

function iecompattest(){
return (document.compatMode && document.compatMode!= "BackCompat ")? document.documentElement : document.body
}

function clearbrowseredge(obj, whichedge){
var edgeoffset=0
if (whichedge== "rightedge "){
var windowedge=ie4 && !window.opera? iecompattest().scrollLeft+iecompattest().clientWidth-15 : window.pageXOffset+window.innerWidth-15
dropmenuobj.contentmeasure=dropmenuobj.offsetWidth
if (windowedge-dropmenuobj.x < dropmenuobj.contentmeasure)
edgeoffset=dropmenuobj.contentmeasure-obj.offsetWidth
}
else{
var topedge=ie4 && !window.opera? iecompattest().scrollTop : window.pageYOffset
var windowedge=ie4 && !window.opera? iecompattest().scrollTop+iecompattest().clientHeight-15 : window.pageYOffset+window.innerHeight-18
dropmenuobj.contentmeasure=dropmenuobj.offsetHeight
if (windowedge-dropmenuobj.y < dropmenuobj.contentmeasure){ //move up?
edgeoffset=dropmenuobj.contentmeasure+obj.offsetHeight
if ((dropmenuobj.y-topedge) <dropmenuobj.contentmeasure) //up no good either?
edgeoffset=dropmenuobj.y+obj.offsetHeight-topedge
}
}
return edgeoffset
}

function populatemenu(what){
if (ie4||ns6)
dropmenuobj.innerHTML=what.join( " ")
}


function dropdownmenu(obj, e, menucontents, menuwidth){
if (window.event) event.cancelBubble=true
else if (e.stopPropagation) e.stopPropagation()
clearhidemenu()
dropmenuobj=document.getElementById? document.getElementById( "dropmenudiv ") : dropmenudiv
populatemenu(menucontents)

if (ie4||ns6){
showhide(dropmenuobj.style, e, "visible ", "hidden ", menuwidth)
dropmenuobj.x=getposOffset(obj, "left ")
dropmenuobj.y=getposOffset(obj, "top ")
dropmenuobj.style.left=dropmenuobj.x-clearbrowseredge(obj, "rightedge ")+ "px "
dropmenuobj.style.top=dropmenuobj.y-clearbrowseredge(obj, "bottomedge ")+obj.offsetHeight+ "px "
}

return clickreturnvalue()
}

function clickreturnvalue(){
if (ie4||ns6) return false
else return true
}

function contains_ns6(a, b) {
while (b.parentNode)
if ((b = b.parentNode) == a)
return true;
return false;
}

function dynamichide(e){
if (ie4&&!dropmenuobj.contains(e.toElement))
delayhidemenu()
else if (ns6&&e.currentTarget!= e.relatedTarget&& !contains_ns6(e.currentTarget, e.relatedTarget))

delayhidemenu()
}

function hidemenu(e){
if (typeof dropmenuobj!= "undefined "){
if (ie4||ns6)
dropmenuobj.style.visibility= "hidden "
}
}

function delayhidemenu(){
if (ie4||ns6)
delayhide=setTimeout( "hidemenu() ",disappeardelay)
}

function clearhidemenu(){
if (typeof delayhide!= "undefined ")
clearTimeout(delayhide)
}

if (hidemenu_onclick== "yes ")
document.onclick=hidemenu

</script>

[解决办法]
帮up
[解决办法]
这么多代码看得头晕，javascript不写;不是好习惯
两个iframe放在不同的div里面，div的zindex不同，试试看