var orgImage = null;
$(document).ready(function () {
    $("div#menu > ul li img:not([src*=active])").hover(
      function () {
        orgImage = this.src;
        this.src = this.src.replace('.jpg', '-over.jpg');
      },
      function () {
        if (orgImage != null) {
          this.src = orgImage;
        }
      }
    )
  });