[jQuery] Simple Filtering Script not working

[Nic Hubbard]

I am working on a simple filtering script that will match the jquery
selector, and find the text inside all the child nodes.  Then hide
those that are not found.

For some reason it is not working, and I am not sure why.  Is there a
better way I could be doing this?

        var obj = $(this);

        $('#filter').keyup(function() {
            var filter = $('#filter').val();
            obj.each(function() {
                if ($(this + ':contains(filter)')) {
                    $(this).show();
                } else {
                    $(this).hide();
                };
            });
        });