function doOnLoad(dir) {
  
  var imageNum = getCookie("img_people");
  
  if (dir == null) {
    dir = "";
  }
  
  if (imageNum == "") {
    imageNum = "0";
  }
  
  if (imageNum == "0") {
    document.getElementById("img_people").src=dir + "../images/people0.jpg";
    setCookie("img_people", "1");
  }
  else if (imageNum == "1") {
    document.getElementById("img_people").src=dir + "../images/people1.jpg";
    setCookie("img_people", "0");
  }
}