function buildsubmenus_horizontal() {
    var menuids = ["treemenu1"]; 
            for (var i = 0; i < menuids.length; i++) {
                var ultags = document.getElementById(menuids[i]).getElementsByTagName("ul")
                for (var t = 0; t < ultags.length; t++) {

                    if (ultags[t].parentNode.parentNode.id == menuids[i]) { //if this is a first level submenu
                        ultags[t].style.top = ultags[t].parentNode.offsetHeight + "px" //dynamically position first level submenus to be height of main menu item
                        ultags[t].parentNode.getElementsByTagName("a")[0].className = "mainfoldericon"
                    }
                    else { //else if this is a sub level menu (ul)
                        ultags[t].style.left = ultags[t - 1].getElementsByTagName("a")[0].offsetWidth + "px" //position menu to the right of menu item that activated it
                        ultags[t].parentNode.getElementsByTagName("a")[0].className = "subfoldericon"
                    }
                    ultags[t].parentNode.onmouseover = function() {
                        this.getElementsByTagName("ul")[0].style.visibility = "visible";
                    }
                    ultags[t].parentNode.onmouseout = function() {
                        this.getElementsByTagName("ul")[0].style.visibility = "hidden";
                    }
                }
            }
        }