Q1801 How can I resize an image

<a href="#" onClick="
this.zoomed = !this.zoomed;
if (document.images) {
  with (document.images['imageName']) {
    if (this.zoomed) {
      sw = width;
      sh = height;
      width=300;
      height=400;
    } else {
      width=sw;
      height=sh;
    }
  }
}
return false;
"><img name="imageName" src="img1.gif" width="100" height="200" alt="click to toggle zoom"<>/a<