var maxWidth = 475;

function scaleImage(im) {

  if (typeof im.naturalWidth == 'undefined') im.naturalWidth = im.width;

  if (im.naturalWidth > maxWidth) {

    im.width = maxWidth;
    im.style.maxWidth = im.naturalWidth + 'px';
    im.className = 'resized';
    im.title = 'Click for Original Size';
    im.onclick = unscaleImage;

  }

}

function unscaleImage() {

  if (this.width == maxWidth) {

    this.width = this.naturalWidth;
    this.style.borderWidth = '0px';
    this.title = 'Click to reduce size';

  } else {

    this.width = maxWidth;
    this.style.borderWidth = '2px';
    this.title = 'Click for Original Size';

  }

}