$(function(){
  $(".img-swap").live('hover', function() {
   if ($(this).attr("class") == "img-swap") {
      this.src = this.src.replace("_up","_dn");
 } else {
      this.src = this.src.replace("_dn","_up");
}
    $(this).toggleClass("dn");
 });
 
  $j(".img-swap").click(function() {
  $j(".img-swap").each(function() {
   this.src = this.src.replace("_dn", "_up");
   });
 this.src = this.src.replace("_dn", "_click");
  });
 
});