/* thanks go to http://www.netlobo.com/div_hiding.html */
function toggleLayer(whichLayer)
{
        if (document.getElementById)
        {
                // this is the way the standards work
                var style2 = document.getElementById(whichLayer).style;         
                style2.display = style2.display? "":"block";
        }
        else if (document.all)
        {
                // this is the way old msie versions work
                var style2 = document.all[whichLayer].style;
                style2.display = style2.display? "":"block";
        }
        else if (document.layers)
        {
                // this is the way nn4 works
                var style2 = document.layers[whichLayer].style;
                style2.display = style2.display? "":"block";
        }
}

function toggleLayers(firstLayer,secondLayer)
{
        if (document.getElementById)
        {
                // this is the way the standards work
                var style1 = document.getElementById(firstLayer).style;         
                var style2 = document.getElementById(secondLayer).style;         
                style1.display = style1.display? "":"none";
                style2.display = style2.display? "":"block";
        }
        else if (document.all)
        {
                // this is the way old msie versions work
                var style1 = document.all[firstLayer].style;
                var style2 = document.all[secondLayer].style;
                style1.display = style1.display? "":"none";
                style2.display = style2.display? "":"block";
        }
        else if (document.layers)
        {
                // this is the way nn4 works
                var style1 = document.layers[firstLayer].style;
                var style2 = document.layers[secondLayer].style;
                style1.display = style1.display? "":"none";
                style2.display = style2.display? "":"block";
        }
}