function RandomBG(path, numImages) {
  var nextNumber = 0;
  var ranNum = Math.floor( Math.random() * numImages ) + 1;
  var imgBg = path + ranNum + '.gif';
  var objTdImg = document.getElementById( 'tdImg' );
  objTdImg.setAttribute( 'background', imgBg );
  nextNumber = ranNum;
}