Redirection on the last Slideshow-Element with Jquery

Answer 1

You forgot to unbind the added click function. Thus the next time you click .last the redirect is performed. Change your code to this. To allow you to unbind only the redirect function.

var lastHandler = function() {
    window.location.replace("[+PJN_next+]");
};

$(document).ready(function() {
    $("#image_nav a:first").attr('id', 'firstSlide');
    $("#image_nav a:last").attr('id', 'lastSlide');

    $(".dritte_ebene li:first").attr('id', 'firstNavi');
    $(".dritte_ebene li:last").attr('id', 'lastNavi');

    //Redirect to the next page
    $("a").click(function() {
        if ($("#lastSlide").hasClass("activeSlide")) {
            $("#weiter").addClass("last").click(lastHandler);
            $('.slide').cycle('pause');
        }
    });

    //Remove "last" if prev is clicked
    $('#zurueck').click(function() {
        $(".last").removeClass("last").unbind('click', lastHandler);
    });
});