Calling Function in a Modular Javascript file triggered undefined object error

Question

I recently started with Modular javascript files. But I am facing an issue when trying to call internal functions. My script is like this

var myTeamMaster=(function(){
    alert(function1());
    var function1=function()
    {
        alert("function1");
    }
    var function2=function()
    {
        alert("function2");
    };
    return
    {
        function1:function1,
        function2:function2
    }
})();

As you can see Im just calling function1() from the alert. Its triggering object expected error. I didnt understand why?