JS ~OO ?

JS ~OO ?

Sorry if this isn't directly pertaining to the jQuery API but more over to JavaScript in general.
I like to keep it elegant so I'm trying my hand at OO-like JS. (much props to Stoyan Stefanov for his book Object-Oriented JavaScript).
My main issues are (obviously) with scoping.
Given:
function SexyObj()
{
        this.sexyFunction = function(){ alert('Too Sexy')};
       
        //initialize
        (function()
        {
                this.sexyFunction();
        }();
};
So, i'm trying to initialize with an anonymous, self-invoking function calling the constructor function there (righ?).
This doesn't work... I would get a "this.sexyFunction()" is not a function error..don't understand why.
Would the answer be to have "sexyFunction" be a private function and then just have a pointer with the "this."?

My object has to initialize with several functions, hence the problem...