define namespace in JS

function regNamespace(namespace) {

    var parts = namespace.split(".");
    var root = "window";

    for (var i = 0; i < parts.length; i++) {
        
        var part = parts[i];

        root = root + "." + part;       

        if (eval(root) == undefined) {
            eval(root + "= {};")
        }
    }
}

regNamespace("MyNS")
regNamespace("MyNS.Funcs")

MyNS.Options = {
    Yes:"Yes",
    No:"No"
};

MyNS.Funcs.show = function () {
    alert("hello");
}