debug.js

// Script written by Drew Noakes -- http://drewnoakes.com

// the div element used for debug output.  created in enableDebug.
var debugDiv;

// call this function from a script within the document for which to enable debug output
function enableDebug() {
  document.write("<div id='debugContent' style='display:block; position:absolute; top:7px; right:7px; padding:10px; width:200px; background:#ccc; color:black; border:solid 1px black;'></div>");
  debugDiv = document.getElementById("debugContent");
  writeClearLink();
}

// writes the string passed to it to the page
function writeDebug(message) {
  if (debugDiv)
    debugDiv.innerHTML += message + "<br\/>";
}

// writes the value of some code expression.
// eg: writeEval("document.location"); // writes "document.location = http://drewnoakes.com"
/*function writeEval(code) {
  writeDebug(code + " = " + eval(code));
}

// writes all of the properties of the object passed to it
function writeDebugObject(object) {
   for (property in object)
      writeDebug(property);
}*/

// clears the debug output.  called either manually or by the user clicking the 'clear' link in the debug div.
function clearDebug() {
  if (debugDiv) {
    debugDiv.innerHTML = "";
    writeClearLink();
  }
}

// writes a link in the debug div that clears debug output
function writeClearLink() {
  writeDebug("<a href='#' onclick='clearDebug(); return false;'>clear</a>");
}