var panels = new Array('panelcom1', 'panelcom2');
    var tabs = new Array('tabcom1', 'tabcom2');
    function displayPanel(nval)
    {
        for(i = 0; i < panels.length; i++)
        {
            document.getElementById(panels[i]).style.display = (nval-1 == i) ? 'block':'none';
            document.getElementById(tabs[i]).className=(nval-1 == i) ? 'tab_sel_com':'tabcom';
        }
    }