I wish my navbar had an effect slideDown instead of fideIn. It is possible?

This is the code with .fideIn:

```
$(document).ready(function () {
    $("#navbar").hide();

    $(window).scroll(function () {
        $("#navbar").fadeIn(500);

        if ($("body").scrollTop() == 0) {
            $("#navbar").fadeOut(500);
        }
    });
});

```

[**Demo**](http://jsfiddle.net/vb986uth/2/)

I tried to change .fadeIn -> slideDown but the effect isn't seen. Why? I make some mistakes? Or it is impossible to put this kind of effect?