/* Script variables */
      var imageArray = new Array();
      var currentImage = 0;

      /* User variables */
      var numImages = 11;
      var sizeX = 333;
      var sizeY = 251;
      var imagePath = "/resources/images/nursery/";
      var fileStub = "ss_nursery_";
      var fileExtension = ".jpg";

      /* Pre-load images */
      if(document.images)
      {
        for (i = 0; i < numImages; i++)
        {
          imageArray[i] = new Image(sizeX, sizeY);
          /* Build image source up from systematic file naming */
          imageArray[i].src = imagePath + fileStub + (i+1) + fileExtension;
        }
      }

      /* Step through the images in the array */
      function imageChange(imageID, step, counterID)
      {

        /* Check that relevant parameters have been passed */
        if (!(imageID) || !(step)) return;

        /* Increment image number - prevent numbers outside of the array */
        currentImage = currentImage + step;
        currentImage = (currentImage < 0) ? numImages - 1: currentImage;
        currentImage = (currentImage >= numImages) ? 0: currentImage;

        /* Update the image */
        if (document.getElementById(imageID))
        {
          document.images[imageID].src = imageArray[currentImage].src;
        }

        /* Update the image counter */
        if (document.getElementById(counterID))
          document.getElementById('numberCounter').innerHTML = currentImage + 1;
      }