// swapable = true - wenn ein ImageSwapping moeglich ist - andernfalls swapable = false
var swapable = false;
if ((parseInt(navigator.appVersion) >= 3) && 
    (navigator.appName == "Netscape")     && 
    (navigator.userAgent.indexOf("ompatib") == -1)) swapable = true;
if ((parseInt(navigator.appVersion) >= 4) && 
    (navigator.appName.indexOf("Internet Explorer") != -1)) swapable = true;

// this function swaps an image (ImgName) - with an image from the overImgArray (overImgArray[index])
function swapover(ImgName, index) {
  if (swapable) {
  document.images[ImgName].src = overImgArray[index].src
  }
}

// this function swaps an image (ImgName) - with an image from the outImgArray (outImgArray[index])
function swapout(ImgName, index) {
  if (swapable) {
  document.images[ImgName].src = outImgArray[index].src
  }
}