// image lists.
var imgN = new Array()
imgN[0] = "images/btn_home_0.jpg"
imgN[1] = "images/btn_about_0.jpg"
imgN[2] = "images/btn_past_0.jpg"
imgN[3] = "images/btn_current_0.jpg"
imgN[4] = "images/btn_future_0.jpg"
var imgS = new Array()
imgS[0] = "images/btn_home_1.jpg"
imgS[1] = "images/btn_about_1.jpg"
imgS[2] = "images/btn_past_1.jpg"
imgS[3] = "images/btn_current_1.jpg"
imgS[4] = "images/btn_future_1.jpg"
// functions
function ChangeImage(image, newImageFile) {
  image.src = newImageFile
}
function PreloadImages() {
  // Create a "dummy" image.
  var preloadedImage = new Image()
  // Load all the pictures into this image, one after another.
  for (var j = 0; j < imgS.length; j++) {
    preloadedImage.src = imgS[j]
  }
}