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";
                        }
                }