function print_r(theObj){
  if(theObj.constructor == Array ||
     theObj.constructor == Object){
    document.write("<ul>")
    for(var p in theObj){
      if(theObj[p].constructor == Array||
         theObj[p].constructor == Object){
document.write("<li>["+p+"] => "+typeof(theObj)+"</li>");
        document.write("<ul>")
        print_r(theObj[p]);
        document.write("</ul>")
      } else {
document.write("<li>["+p+"] => "+theObj[p]+"</li>");
      }
    }
    document.write("</ul>")
  }
}

function printStackTrace() {
  var callstack = [];
  var isCallstackPopulated = false;
  try {
    i.dont.exist+=0; //doesn't exist- that's the point
  } catch(e) {
    if (e.stack) { //Firefox
      var lines = e.stack.split("\n");
      for (var i=0, len=lines.length; i<len; i++) {
        if (lines[i].match(/^\s*[A-Za-z0-9\-_\$]+\(/)) {
          callstack.push(lines[i]);
        }
      }
      //Remove call to printStackTrace()
      callstack.shift();
      isCallstackPopulated = true;
    }
    else if (window.opera && e.message) { //Opera
      var lines = e.message.split("\n");
      for (var i=0, len=lines.length; i<len; i++) {
        if (lines[i].match(/^\s*[A-Za-z0-9\-_\$]+\(/)) {
          var entry = lines[i];
          //Append next line also since it has the file info
          if (lines[i+1]) {
            entry += " at " + lines[i+1];
            i++;
          }
          callstack.push(entry);
        }
      }
      //Remove call to printStackTrace()
      callstack.shift();
      isCallstackPopulated = true;
    }
  }
  if (!isCallstackPopulated) { //IE and Safari
    var currentFunction = arguments.callee.caller;
    while (currentFunction) {
      var fn = currentFunction.toString();
      var fname = fn.substring(fn.indexOf("function") + 8, fn.indexOf("(")) || "anonymous";
      callstack.push(fname);
      currentFunction = currentFunction.caller;
    }
  }
  output(callstack);
}

function output(arr) {
  //Optput however you want
  alert(arr.join("nn"));
}