jQuery捕获被点击元素的ID

I am trying to capture the ID of the element being clicked when a user clicks on an element which allows him to leave a page. The idea is to then record this using Ajax. The script below seems to be working fine as long as the element has an ID, but it does not seem to be able to climb the DOM to find an ancestor's ID if it has not. What am I doing wrong?I am trying to capture the ID of the element be