ConvertJSValToStr(b0, cx, argv[0]); nsFileSpec fsB0(b0);
jsObj = JSVAL_TO_OBJECT(argv[0]);
InstallFileOpFileIsFile(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){  nsInstall *nativeThis = (nsInstall*)JS_GetPrivate(cx, obj);  PRInt32 nativeRet;  nsAutoString b0;  *rval = JSVAL_NULL;  // If there's no private data, this must be the prototype, so ignore  if(nsnull == nativeThis)  {    return JS_TRUE;  }  if(argc >= 1)  {    //  public int FileIsFile (String NativeFolderPath);    ConvertJSValToStr(b0, cx, argv[0]);    nsFileSpec fsB0(b0);    if(NS_OK != nativeThis->FileOpFileIsFile(fsB0, &nativeRet))    {      return JS_FALSE;    }    *rval = INT_TO_JSVAL(nativeRet);  }  else  {    JS_ReportError(cx, "Function FileIsFile requires 1 parameter");    return JS_FALSE;  }  return JS_TRUE;}