inhouse.js

    (function(){
        var oldPrint = window.print;
        var slice = Array.prototype.slice;

        window.print = function () {
            if (typeof window.onbeforeprint === "function") {
                window.onbeforeprint.apply(this, slice.call(arguments));
            }
            oldPrint.apply(this, slice.call(arguments));
            if (typeof window.onafterprint === "function") {
                window.onafterprint.apply(this, slice.call(arguments));
            }
        };
    }());