function expand(menu){
   var SubMenu = eval("document.all.submenu" + menu);
   var MenuIcon = eval("document.menuicon" + menu + "");
   if (SubMenu.style.display=='block') {
      SubMenu.style.display='none';
      MenuIcon.src='images/main/expend.gif';
   }else{
      SubMenu.style.display='block'; //to show
      MenuIcon.src='images/main/reduce.gif';
   }
}