function imgSwapOn(imgName,imgFile) {
   imgName.src='images/'+imgFile+'-on.gif';
}

function imgSwapOff(imgName,imgFile) {
   imgName.src='images/'+imgFile+'-off.gif';
}

function doPreload()  {
   var the_images = new Array(
   "images/linkHome-on.gif", 
   "images/linkAboutBiomatech-on.gif", 
   "images/linkServices-on.gif", 
   "images/linkContact-on.gif",
   "images/linkAboutNAMSA-on.gif")
      
   preloadImages(the_images);
}

function preloadImages(theImages)  {
   for(i = 0; i < theImages.length; i++)  {
      var theImage = new Image();
      theImage.src = theImages[i];
   }
}