HTML5 drag height on window resize

i have this bit of code: var dragHeight = window.innerHeight - parseInt(jQuery("#drag_area").css("margin-top")) - 5; to set the drag height for each browser size. but say i start the browser not maximized and then maximize it, the drag height is still开发者_C百科 the same as previous and wont let me drag all the way to the bottom of screen, any help would be appreciated. thanks

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It could be something like this...

var dragHeight,
    calcDragHeight = function() {
        dragHeight = window.innerHeight - parseInt($("#drag_area").css("margin-top")) - 5;
    };

calcDragHeight();

$(function() {
    $(window).resize(function() {calcDragHeight();});
});