Passing multiple parameters to AJAX call

I'm trying to pass two parameters to the url in my Ajax call and it's not working. What is wrong with my format?  Thank you

function getData() 
            {
            return $.ajax({
                    url: "/Books/GetBookList/" + "<%=ca.ID%>" + "&<%=ca.Title%>",
                    type: "GET", 
                    dataType: "json",
                    success: ShowBooks,
                    error: function (jqXHR, textStatus, errorThrown) { 
                    }
                 });
                }