diff --git a/tools/test-harness/xpcshell-simple/README b/tools/test-harness/xpcshell-simple/README
index 87129cf408e..a359b3c8d58 100644
--- a/tools/test-harness/xpcshell-simple/README
+++ b/tools/test-harness/xpcshell-simple/README
@@ -2,5 +2,6 @@ Simple xpcshell-based test harness
 
 converted from netwerk/test/unit
 
-current project page at http://wiki.mozilla.org/SoftwareTesting:Tools:Simple_xpcshell_test_harness
+Some documentation at http://developer.mozilla.org/en/docs/Writing_xpcshell-based_unit_tests
+See also http://wiki.mozilla.org/SoftwareTesting:Tools:Simple_xpcshell_test_harness
 
diff --git a/tools/test-harness/xpcshell-simple/example/Makefile.in b/tools/test-harness/xpcshell-simple/example/Makefile.in
index 58f756dde62..e77fa45e061 100644
--- a/tools/test-harness/xpcshell-simple/example/Makefile.in
+++ b/tools/test-harness/xpcshell-simple/example/Makefile.in
@@ -36,7 +36,7 @@
 #
 # ***** END LICENSE BLOCK *****
 
-DEPTH		= ../..
+DEPTH		= ../../../..
 topsrcdir	= @top_srcdir@
 srcdir		= @srcdir@
 VPATH		= @srcdir@
diff --git a/tools/test-harness/xpcshell-simple/head.js b/tools/test-harness/xpcshell-simple/head.js
index a1e297c1a05..a47988981b4 100644
--- a/tools/test-harness/xpcshell-simple/head.js
+++ b/tools/test-harness/xpcshell-simple/head.js
@@ -37,7 +37,10 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
-// This file contains common code that is loaded with each test file.
+/* This file contains common code that is loaded with each test file.
+ * See http://developer.mozilla.org/en/docs/Writing_xpcshell-based_unit_tests
+ * for more informaton
+ */
 
 var _quit = false;
 var _fail = false;
@@ -59,13 +62,7 @@ _TimerCallback.prototype = {
   }
 };
 
-function do_timeout(delay, expr) {
-  var timer = Components.classes["@mozilla.org/timer;1"]
-                        .createInstance(Components.interfaces.nsITimer);
-  timer.initWithCallback(new _TimerCallback(expr), delay, timer.TYPE_ONE_SHOT);
-}
-
-function do_main() {
+function _do_main() {
   if (_quit)
     return;
 
@@ -80,15 +77,23 @@ function do_main() {
     thr.processNextEvent(true);
 }
 
-function do_quit() {
+function _do_quit() {
   dump("*** exiting\n");
 
   _quit = true;
 }
 
+/************** Functions to be used from the tests **************/
+
+function do_timeout(delay, expr) {
+  var timer = Components.classes["@mozilla.org/timer;1"]
+                        .createInstance(Components.interfaces.nsITimer);
+  timer.initWithCallback(new _TimerCallback(expr), delay, timer.TYPE_ONE_SHOT);
+}
+
 function do_throw(text) {
   _fail = true;
-  do_quit();
+  _do_quit();
   dump("*** CHECK FAILED: " + text + "\n");
   var frame = Components.stack;
   while (frame != null) {
@@ -98,18 +103,18 @@ function do_throw(text) {
   throw Components.results.NS_ERROR_ABORT;
 }
 
-function do_check_neq(_left, _right) {
-  if (_left == _right)
-    do_throw(_left + " != " + _right);
+function do_check_neq(left, right) {
+  if (left == right)
+    do_throw(left + " != " + right);
 }
 
-function do_check_eq(_left, _right) {
-  if (_left != _right)
-    do_throw(_left + " == " + _right);
+function do_check_eq(left, right) {
+  if (left != right)
+    do_throw(left + " == " + right);
 }
 
-function do_check_true(_condition) {
-  do_check_eq(_condition, true);
+function do_check_true(condition) {
+  do_check_eq(condition, true);
 }
 
 function do_test_pending() {
@@ -120,5 +125,5 @@ function do_test_pending() {
 function do_test_finished() {
   dump("*** test finished\n");
   if (--_tests_pending == 0)
-    do_quit();
+    _do_quit();
 }
diff --git a/tools/test-harness/xpcshell-simple/tail.js b/tools/test-harness/xpcshell-simple/tail.js
index 8a2410f7387..c8046429532 100644
--- a/tools/test-harness/xpcshell-simple/tail.js
+++ b/tools/test-harness/xpcshell-simple/tail.js
@@ -40,7 +40,7 @@ try {
   do_test_pending();
   run_test();
   do_test_finished();
-  do_main();
+  _do_main();
 } catch (e) {
   _fail = true;
   dump(e + "\n");