通过jQuery ajax()向PHP发送多个复选框数据

I want to submit a POST form that contains a textarea field and an input field(s) (type="checkbox" with an arbitrary/variable number of checkboxes) on my website via jQuery's .ajax(). PHP receives the textarea data and the ajax response is correctly displayed to the user. However, it seems that PHP is not receiving the checkbox data (was it checked, or not). How can I get this to work? Here is the code I have:I want to submit a POST form that contains a te