// Global variables for layer access
    var layer = new String();
    var style = new String();

    // Set appropriate layer variables based on browser
    function check(){
      if(navigator.userAgent.indexOf("MSIE") != -1){
        layer = ".all";
        style = ".style";
      }else if(navigator.userAgent.indexOf("Nav") != -1){
        layer = ".layers";
        style = "";
      }
    }

    // Rollover link and display image..
    function rollover(layerRef, state){
      eval("document" + layer + "['" + layerRef + "']" + style + 
".visibility = '" + state + "'");
    }