Simple fixed header after trigger point

stickyheader.js

(function(){
    var triggerElement = $(".container") //element to he used to trigger the fixed header
      , header = $(".header") //element of header
      , stickyClass = "stickit" // class to be used to give the fixed header a fixed position

    $(window).scroll(function(){ 
        var offset = 0,sticky = false,top = $(window).scrollTop();
        if (triggerElement.offset().top < top) {
            header.addClass(stickyClass)
            sticky = true;
        } else {
            header.removeClass(stickyClass).removeAttr('style');
        }
    });
})()