if (document.images) {
   aboutOn = new Image();
   aboutOn.src = "/images/header/nav/about_us_on.gif";
   infoOn = new Image();
   infoOn.src = "/images/header/nav/info_on.gif";
   productsOn = new Image();
   productsOn.src = "/images/header/nav/products_on.gif";
   professionalsOn = new Image();
   professionalsOn.src = "/images/header/nav/professionals_on.gif";
   
   aboutOff = new Image();
   aboutOff.src = "/images/header/nav/about.gif";
   infoOff = new Image();
   infoOff.src = "/images/header/nav/info.gif";
   productsOff = new Image();
   productsOff.src = "/images/header/nav/products.gif";
   professionalsOff = new Image();
   professionalsOff.src = "/images/header/nav/professionals.gif";
}


function swapImage(imgName,newImage) {
   if (document.images) {
      eval('document.' + imgName + '.src = ' + newImage + '.src');
   }
}