if (document.images)
            {
            arrow_off = new Image(28, 28);
            arrow_off.src = "/snpworld/images/smallArrowDown.gif";
            arrow_on = new Image(28, 28);
            arrow_on.src = "/snpworld/images/smallArrowUp.gif";

            arrow2_off = new Image(28, 28);
            arrow2_off.src = "/snpworld/images/smallArrowUp.gif";
            arrow2_on = new Image(28, 28);
            arrow2_on.src = "/snpworld/images/smallArrowDown.gif";
            } 

            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 toggleImage(imageName)
            {
            if (document.images)
            {
            if (document[imageName].src == eval(imageName + "_off.src")) {
            document[imageName].src = eval(imageName + "_on.src");
            } else {
            document[imageName].src = eval(imageName + "_off.src");
            }
            }          
            }      

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