//preload images
function PreloadImages() {
  var imglist = new Array("expedice", "aljaska", "np_denali", "mount_mckinley", "notes");
  var pic     = new Array(imglist.length);
  if (document.images){
    for (i = 0; i < imglist.length; i++) {
      pic[i] = new Array();
      pic[i][0] = new Image();
      pic[i][0].src = './images/' + imglist[i] + '_click.jpg';
      pic[i][1] = new Image();
      pic[i][1].src = './images/' + imglist[i] + '_over.jpg';
    } //for
  }  //if
} //function