if (!nativeThis) return JS_FALSE;
InstallResetError(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){  nsInstall *nativeThis =    (nsInstall*)JS_GetInstancePrivate(cx, obj, &InstallClass, argv);  if (!nativeThis)    return JS_FALSE;  *rval = JSVAL_VOID;  // If there's no private data, this must be the prototype, so ignore  if (!nativeThis)    return JS_TRUE;  // Supported forms:  //    void resetError()  //    void resetError(int error)  int32 val = 0;  if ( argc >= 1 )    JS_ValueToECMAInt32(cx, argv[0], &val);  nativeThis->ResetError(val);  return JS_TRUE;}