var numberScriptLoaded;

(function () {

    var privateNumberScriptLoaded;

    if (!numberScriptLoaded) {

        numberScriptLoaded = 1; // 1, not 0

    }

    else {

        ++numberScriptLoaded;

    }

​

    // Note that all `window` properties are globals,

    // so here, it works even without the prefix

    privateNumberScriptLoaded = numberScriptLoaded;

  console.log("Option 2: privateNumberScriptLoaded = " +

    privateNumberScriptLoaded);

})();