responsive.js

var reflowDocument = function () {
    var viewportWidth = jQuery(window).width();

    // do stuff here
};

jQuery(document).ready(function($) {
    var reflowTimer = null;

    $(window).on('resize', function () {
        clearTimeout(reflowTimer);
        reflowTimer = setTimeout(reflowDocument, 100);
    });

    // First reflow
    reflowDocument();
});