Column index for onClick event in header menu

How do you obtain the Columnindex where the onClick menu event occured. For columns in regular cells in the data area it’s this.ClickedColumnIndex, however that is not defined for dhtmlXMenuObject attached to the header area.

    function AddGridHeaderMenu(oGrid, nTableType, sDatabaseID) {
        var menuHeader;
        var sURLMenu;

        menuHeader = new dhtmlXMenuObject();                   // Grid context menu initialization\setup
        oGrid.hdr.id = oGrid.id + "_HeaderContextZone";
        menuHeader.ParentID = oGrid.id;

        menuHeader.setIconsPath(URL_MENU_IMAGES);
        menuHeader.setSkin(SKIN_NAME);
        menuHeader.setOverflowHeight(20);
        menuHeader._scrollUpTMTime = 10;
        menuHeader._scrollDownTMTime = 10;

        menuHeader.renderAsContextMenu();

        menuHeader.addContextZone(oGrid.hdr.id);

        menuHeader.attachEvent("onClick", function (sID, sZoneID, sKeyState) {
            switch (sID.toUpperCase()) {
                case "MNUADDABOVE": return AddSignalType(this.ClickedRowID, true);
                case "MNUADDBELOW": return AddSignalType(this.ClickedRowID, false);
                case "MNUREMOVE": return RemoveSignalType(this.ClickedRowID);
                case "MNUADDRIGHT": return AddTimeToManage(this.ClickedColumnIndex, true);
                case "MNUADDLEFT": return AddTimeToManage(this.ClickedColumnIndex, false);
                default: alert("Translate(Unhandled_menu_click_event)");
                    debugger;
            }
        });

You may try to use the onBeforeContextMenu event. It will return the obj of the clicked element.
docs.dhtmlx.com/doku.php?id=dhtm … ontextmenu