var icon = null;
		      function show_icon(file, text, top)
		      {
		        icon = document.getElementById('float_icon');
		        document.getElementById('float_icon_img').src = 'data/icon/' + file + '.jpg';
		        document.getElementById('float_icon_img').alt = text;
		        document.getElementById('float_icon_img').title = text;
            icon.style.top = top + 'px';
            if (file)
            {
              icon.style.display = '';
            }
          }
          
          function hide_icon()
          {
            icon.style.display = 'none';
            icon = null;
          }