Function Firing Only Once

Function Firing Only Once

I've got 10 pages of purple links on Google, so I'm not being lazy. 

var count_element = $("input:empty").length;
        $(".panel-container").keyup(function () {
            $("#total").text(count_element);
        });

The above function works great, but only once. .keyup is tied to the div containing all form elements, so whenever the key comes up I thought it would recalculate the variable and output it again, but it only fires once, and the total stays the the same no matter how may fields I fill in. I've tried .click, .blur and a bunch of other events, no go. Please help! Thanks.