Fred's Javascript scoping

gistfile1.js

function Fred(state){

    var innerState = state;

    return {
        getState: function() {
            return innerState;
        },
        setState: function(newState){
            innerState = newState;
        }

    };

}

var fred = new Fred("OK");
console.log(fred.getState());

fred.setState("Confused");
console.log(fred.getState());

//Both undefined in this scope
console.log(this.innerState); 
console.log(fred.innerState);