function toggleChanges() {
  if (document.getElementById("changes").style.display == "none") {
    document.getElementById("changes").style.display  = "block";
    document.getElementById("contentWithoutChanges").style.display = "none";
    document.getElementById("show_changes").style.display  = "none";
    document.getElementById("hide_changes").style.display = "inline";
  } else {
    document.getElementById("changes").style.display  = "none";
    document.getElementById("contentWithoutChanges").style.display = "block";
    document.getElementById("show_changes").style.display  = "inline";
    document.getElementById("hide_changes").style.display = "none";
  }
}

function quickReference(src) {
  window.open( 
    src.href,
    "markdown",
    "height=550,width=750,channelmode=0,dependent=0," +
    "directories=0,fullscreen=0,location=0,menubar=0," +
    "resizable=1,scrollbars=1,status=1,toolbar=0" 
  );
}