function imageButton (tag, query)
{
  var url = tag.noSpaces () + ".htm";
  // JavaScript has an "== undefined" construct - but it works with IE 5.5 and not 5.0:
  //   if (query == undefined)
  // I'll check the number of arguments passed instead
  if (arguments.length == 2)
    url += "?" + escape (query);

  var overImage = new Image();
  overImage.src = "Images/Button" + tag.noSpaces () + "Over.gif";

  put ("<a onmouseover='" + namer ("imageButton", tag) + ".src=\"Images/Button" + tag.noSpaces () + "Over.gif\"' " +
          "onmouseout='" + namer ("imageButton", tag) + ".src=\"Images/Button" + tag.noSpaces () + "Normal.gif\"' " +
          "target='mainFrame' href='" + url + "'>");
  put ("<img name='" + namer ("imageButton", tag) + "' src='Images/Button" + tag.noSpaces () + "Normal.gif' alt='" + tag + "' border=0></a>");
}