var _visibleBox = ".boxy-wrapper:visible";
$(document).ready(
    function() 
    {
        $("a.popup-content").boxy({filter: "#content_main", modal: true, title: false, fixed: false});
   });

$(window).resize(
    function()
    {
        $(_visibleBox).css({
        "left": (($(window).width() / 2) - ($(_visibleBox).width() / 2)) +  $(window).scrollLeft() + "px",
        "top": (($(window).height() / 2) - ($(_visibleBox).height() / 2)) +  $(window).scrollTop()  + "px"});
    }
);