how to Change Custom List Close Button

$(document).ready(function() {

    var button = $("input[value=Close]");
    // change redirection behavior
        button.removeAttr("onclick");
        button.click(function() {
            var elementName = $(this).attr("name");
            var aspForm = $("form[name=aspnetForm]");
            var oldPostbackUrl = aspForm.get(0).action;
            var currentSourceValue = GetUrlKeyValue("Source", true, oldPostbackUrl);
            var newPostbackUrl = oldPostbackUrl.replace(currentSourceValue, "thank.aspx");

            if (!PreSaveItem()) return false;
            WebForm_DoPostBackWithOptions(new WebForm_PostBackOptions(elementName, "", true, "", newPostbackUrl, false, true));
        });

});