To see the content POST data trasferred by jQuery

You can use the Network tab and look at the params tab as shown below (this was a get request to google where I search for the word hello).

_{(source: gyazo.com)}

There are various tools you can use to capture such information. I use a plugin for Firefox called Live HTTP Headers, which lets you view the HTTP headers that are being transferred in each request, so you would be able to view your post variable.

Firebug can also be used, it is also a plugin available for Firefox. Select the Net tab, then select All. Here you will see a list of all requests. Now you can expand each request to view the headers (and hence the post variables).