[jQuery] Refactoring Functions

[Chris P]

I wanted a script that would make a sticky footer, and it worked
perfectly with this (where 341 is the elements to offset).

var height = $(document).height();
var height = height - 341;
$('#footer').css('margin-top', height);

Then I want this code to re-run on browser resize.  I also want to
refactor the code above to use a second time.  The problem is that (1)
it doesn't re-run on browser resize and (2) I don't want to duplicate
code.  How can I refactor?

var height = $(document).height();
var height = height - 341;
$('#footer').css('margin-top', height);

$(window).resize(function(){
        var height = $(document).height();
        var height = height - 341;
        $('#footer').css('margin-top', height);
});