// Set global var with current year
var currdate = new Date();
var curryear = currdate.getYear();
if (curryear < 1000) curryear += 1900;

browser = (((navigator.appName == "Netscape") && (parseInt(navigator.appVersion) >= 3 )) ||
          ((navigator.appName == "Microsoft Internet Explorer") && (parseInt(navigator.appVersion) >= 4 )));

if (browser) {
  if (document.images) {

    // normal image
    btn01nrm = new Image();
    btn01nrm.src = "images/btn01nrm.jpg";
    btn02nrm = new Image();
    btn02nrm.src = "images/btn02nrm.jpg";
    btn03nrm = new Image();
    btn03nrm.src = "images/btn03nrm.jpg";
    btn04nrm = new Image();
    btn04nrm.src = "images/btn04nrm.jpg";
    btn05nrm = new Image();
    btn05nrm.src = "images/btn05nrm.jpg";
    btn06nrm = new Image();
    btn06nrm.src = "images/btn06nrm.jpg";
    btn07nrm = new Image();
    btn07nrm.src = "images/btn07nrm.jpg";

    // hover image
    btn01hov = new Image();
    btn01hov.src = "images/btn01hov.jpg";
    btn02hov = new Image();
    btn02hov.src = "images/btn02hov.jpg";
    btn03hov = new Image();
    btn03hov.src = "images/btn03hov.jpg";
    btn04hov = new Image();
    btn04hov.src = "images/btn04hov.jpg";
    btn05hov = new Image();
    btn05hov.src = "images/btn05hov.jpg";
    btn06hov = new Image();
    btn06hov.src = "images/btn06hov.jpg";
    btn07hov = new Image();
    btn07hov.src = "images/btn07hov.jpg";
  }
}

function changeImage(imgDocID,imgObjName) {
  document.images[imgDocID].src = eval(imgObjName + ".src");
}