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