function changeImage(targetImg1, newImg1) {
  if (document[targetImg1]) {
    document[targetImg1].src = eval(newImg1 + ".src");
  }
}

// Pre-load graphics
home_on = new Image(); home_on.src = "../images/buttons/home3_on.gif";
home_off = new Image(); home_off.src = "../images/buttons/home3.gif";
salebarn_on = new Image(); salebarn_on.src = "../images/buttons/salebarn_on.gif";
salebarn_off = new Image(); salebarn_off.src = "../images/buttons/salebarn7.gif";
facilities_on = new Image(); facilities_on.src = "../images/buttons/facilities_on.gif";
facilities_off = new Image(); facilities_off.src = "../images/buttons/facilities.gif";
staff_on = new Image(); staff_on.src = "../images/buttons/staff3_on.gif";
staff_off = new Image(); staff_off.src = "../images/buttons/staff3.gif";
events_on = new Image(); events_on.src = "../images/buttons/events3_on.gif";
events_off = new Image(); events_off.src = "../images/buttons/events3.gif";
lessons_on = new Image(); lessons_on.src = "../images/buttons/lessons_on.gif";
lessons_off = new Image(); lessons_off.src = "../images/buttons/lessons.gif";
camp_on = new Image(); camp_on.src = "../images/buttons/camp3_on.gif";
camp_off = new Image(); camp_off.src = "../images/buttons/camp3.gif";
results_on = new Image(); results_on.src = "../images/buttons/results_on.gif";
results_off = new Image(); results_off.src = "../images/buttons/results.gif";