function AddMessage () {
  var inputLine = getInputLine();

  var req = getXMLhttpRequestObject();
  req.open("GET", "/cgi-bin/chat4.cgi?message=" + inputLine.value, null);
  req.send(null);

  parseMessageReply(req.responseText);

  inputLine.value = ''; setInputFocus();

  return false;
} // AddMessage
// --------------------------------------------------------
// private subs
// --------------------------------------------------------
function parseMessageReply (rText) {
   var list = rText.split("\n");
   for (var i=0; i<list.length; i++) {
     if (list[i] != '') {
       var line = list[i].split("\t");
       writeLine(line[0] + ": " + line[1] + ': ' + line[2]);
     }
   }

} // parseMessageReply
// --------------------------------------------------------
function getInputLine () {
  return ( document.getElementById('inputLine') );
//  return (inputLine);
} // getInputLine
// --------------------------------------------------------
function setInputFocus () {
   var inputLine = getInputLine(); inputLine.focus();
} // SetInputFocus
// --------------------------------------------------------
function writeLine (line, widget) {

  // get output widget    
  widget            = widget || 'Output';
  var outputWidget  = document.getElementById(widget);

  // create a new p containing the text
  var newLine = document.createElement("p");
  var text    = document.createTextNode(line);

  // set class="chatOutputLine"
  newLine.setAttribute("class",     "chatOutputLine"); // for Firefox
  newLine.setAttribute("className", "chatOutputLine"); // for IE

  // and append it to the tree (=write)
  newLine.appendChild(text); 
  outputWidget.appendChild(newLine);
} // writeLine
// --------------------------------------------------------
function getXMLhttpRequestObject () {
  var ret
  
  // for MS Internet explorer
  var msxml = [
    "Msxml2.XMLHTTP.5.0", "Msxml2.XMLHTTP.4.0", "Msxml2.XMLHTTP.3.0",
    "Msxml2.XMLHTTP", "Microsoft.XMLHTTP" ];
  
  if (window.ActiveXObject) {
    for (var i=0; i<msxml.length; i++) {
      try {
        ret = new ActiveXObject(msxml[i]);
        break;
      } catch(e) {}
    } // for
  } // if

  // for firefox and mozilla
  ret = ret ? ret : new XMLHttpRequest();

  return ret
} // getXMLhttpRequestObject
// --------------------------------------------------------