//variable to hold info for the browser
        var browserType = new BrowserType();
        
        //arrays to hold dropdown menus and dropout menus
        var dropDownMenus = new Array();
        var dropOutMenus = new Array();
        
        //menus to create
        dropDownMenus[0] = "dropDownMenu0";
        //dropDownMenus[1] = "dropDownMenu1";
        //dropDownMenus[2] = "dropDownMenu2";
        //dropDownMenus[3] = "dropDownMenu3";
        
        //dropOutMenus[0] = "dropOutMenu0";
        
        
        //variables to control css/dhtml differences in browsers
        if(browserType.ns4) {
                var doc = "document";
                var sty = "";
        } else if(browserType.ie4) {
                var doc = "document.all";
                var sty = ".style";
        }
        //show menulayer
        function showMenuLayer(layerToShow, layerType, parentLayer) {
                hideAllMenuLayers(layerToShow, parentLayer);
                if (layerType == 'dropDownMenu') {
                        styleObj = eval(doc + "['" + dropDownMenus[layerToShow] + "']" + sty);
                        showDiv(styleObj)
                } else if (layerType == 'dropOutMenu') {
                        styleObj = eval(doc + "['" + dropOutMenus[layerToShow] + "']" + sty);
                        showDiv(styleObj)
                }                       
        }
        //hide all menlayers
        function hideAllMenuLayers(dropOutToKeep, dropDownToKeep) {
                //hide all dropOutMenus
                for (i=0; i < dropOutMenus.length; i++) {
                        if (dropOutToKeep != i) {
                                styleObj = eval(doc + "['" + dropOutMenus[i] + "']" + sty);
                                hideDiv(styleObj)
                        }
                }
                //hide all dropDownMenus
                for (i=0; i < dropDownMenus.length; i++) {
                        if (dropDownToKeep != i) {
                                styleObj = eval(doc + "['" + dropDownMenus[i] + "']" + sty);
                                hideDiv(styleObj)
                        }
                }
        }
        
        //shows a layer
        function showDiv(styleObj) {
                if (browserType.ie4) styleObj.visibility = "visible";
                if (browserType.ns4) styleObj.visibility = "show";
        }
        
        //hides a layer
        function hideDiv(styleObj) {
                styleObj.visibility = "hidden";
        }
        
        //trap clickevent not catched by any object
        function defaultClickHandler() {
                hideAllMenuLayers(-1,-1);
        }
        function BrowserType() {
          var agent = navigator.userAgent.toLowerCase();
          this.major = parseInt(navigator.appVersion);
          this.minor = parseFloat(navigator.appVersion);
          this.ns = ((agent.indexOf('mozilla')!=-1) && ((agent.indexOf('spoofer')==-1) && (agent.indexOf('compatible') == -1)));
          this.ns2 = (this.ns && (this.major == 3));
          this.ns3 = (this.ns && (this.major == 3));
          this.ns4b = (this.ns && (this.minor < 4.04));
          this.ns4 = (this.ns && (this.major >= 4));
          this.ie = (agent.indexOf("msie") != -1);
          this.ie3 = (this.ie && (this.major == 2));
          this.ie4 = (this.ie && (this.major >= 4));
          this.op3 = (agent.indexOf("opera") != -1);
          this.win = (agent.indexOf("win")!=-1);
          this.mac = (agent.indexOf("mac")!=-1);
          this.unix = (agent.indexOf("x11")!=-1);
        }
        //trap click event not trapped by any object
        if (browserType.ie4) document.onclick = defaultClickHandler;
        if (browserType.ns4) {
                document.captureEvents(Event.MOUSEUP);
                document.onmouseup=defaultClickHandler; 
        }