diff --git a/mozilla/xpcom/sample/nsSample.js b/mozilla/xpcom/sample/nsSample.js
new file mode 100644
index 00000000000..f22459c9e64
--- /dev/null
+++ b/mozilla/xpcom/sample/nsSample.js
@@ -0,0 +1,86 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+function mySample() {
+    /* use this to execute code a la C++'s SetValue */
+    this.value getter= function () {
+        dump ("Getting value\n");
+        return this.val;
+    };
+
+    this.value setter= function (newval) {
+        dump("Setting value to " + newval + "\n");
+        return this.val = newval;
+    };
+}
+
+mySample.prototype.val = "<default value>";
+mySample.prototype.writeValue = function (aPrefix) {
+    dump("mySample::writeValue => " + aPrefix + this.val + "\n");
+}
+mySample.prototype.poke = function (aValue) {
+    this.val = aValue;
+}
+/* until bug 14460 is fixed, must use QueryInterface, not queryInterface */
+mySample.prototype.QueryInterface = function(iid) {
+    if (iid.equals(Components.interfaces.nsISample) ||
+        iid.equals(Components.interfaces.nsISupports))
+        return this;
+    throw Components.results.NS_ERROR_NO_INTERFACE;
+}
+
+var myModule = {
+    RegisterSelf:function (compMgr, fileSpec, location) {
+        dump("RegisterSelf(" + Array.prototype.join.apply(arguments, ",") + 
+             ")\n");
+        try {
+            compMgr.registerComponentWithType(this.myCID,
+                                              "Sample JS Component",
+                                              "mozilla.jssample.1", fileSpec,
+                                              location, true, true, 
+                                              "text/javascript");
+        } catch (e) { 
+            dump(" FAILURE[" + e + "]");
+        }
+        dump("RegisterSelf done\n");
+    },
+
+    GetClassObject:function (compMgr, cid, iid) {
+        dump("GetClassObject(" + Array.prototype.join.apply(arguments, ",") +
+             ")\n");
+
+        if (!cid.equals(this.myCID)) {
+            dump("GetClassObject: CID mismatch:\nmine:\t" + this.myCID +
+                 "\nin:\t" + cid + "\n");
+            throw Components.results.NS_ERROR_NO_INTERFACE;
+        }
+
+        dump("GetClassObject: have right CID\n");
+        if (iid.equals(Components.interfaces.nsIFactory)) {
+            dump("JS: looking for factory (" + iid + ")\n");
+            return this.myFactory;
+        }
+        dump("GetClassObject: IID mismatch:\nfact:\t" +
+             Components.interfaces.nsIFactory + "\nin:\t" +
+             iid + "\n");
+        throw Components.results.NS_ERROR_NOT_IMPLEMENTED;
+    },
+
+    /* CID for this class */
+    myCID:Components.ID("{dea98e50-1dd1-11b2-9344-8902b4805a2e}"),
+
+    /* factory object */
+    myFactory:{
+        CreateInstance:function (outer, iid) {
+            dump ("JS: CreateInstance(" 
+                  + Array.prototype.join.apply(arguments, ",") + ")\n");
+            if (outer != null) {
+                throw Components.results.NS_ERROR_NO_AGGREGATION;
+            }
+            return new mySample();
+        }
+    }
+};
+    
+function NSGetModule(compMgr, fileSpec) {
+    return myModule;
+}