(function() {

   doSomething();

})()

// or ...


//NOTE: This is basically doing the same thing, but we can gain a tiny bit performance, because we directly
//pass the current window, and document instances to the function, instead of making it iterate
//through the scope

(function(window,document,undefined) {

   doSomething();

})(this,document) // these are the arguments being passed to the function at the beginning