function bringUp(o, grp, img){

  var objs;
  var raisedImg='grp'+grp+'_raised';
  var raisedLink='grp'+grp+'_showing';

  // Remove any images which are already raised:
  objs=$$('.'+raisedImg);
  for(var i=0; i<objs.length; i++) objs[i].removeClassName(raisedImg);

  // Add raisedImg class to named Image:
  objs=$$('.grp'+grp+'_img'+img);
  for(var i=0; i<objs.length; i++) objs[i].addClassName(raisedImg);


  // Remove any links which are already raised:
  objs=$$('.'+raisedLink);
  for(var i=0; i<objs.length; i++) objs[i].removeClassName(raisedLink);

  // Add raisedLink class to this link:
  o.addClassName(raisedLink);
}