how to view what gets transmitted with a form using POST

[Datapunter]

When i look at a webpage containing a form using POST,
i can examine the page and see the form and input fields,
but how can i see exactly what gets transmitted when a user presses submit ?

I need to see it to reproduce it like in case i want to make an auto-login myself and the login is such a form. Examining the page alone isn't always sufficient because sometimes there's some javascript involved.

So i want to see what actually gets transmitted.

[Trilobite]

You want to see all the bytes that leave your pc ?

You need a Network Analyzer program, there should be a few freeware version via google, if that is what you mean ?

[GotaFancy?]

I assume you're looking for something along the lines of what Trilobite said, however just in case, I presume you're aware that if you change method from POST to GET then the form contents are displayed in the URL?

Also, javascript is 100% client side, so there is nothing that cannot be worked out from examining the javascript (though it will not necessarily be clear/easy).

[Blade]

You need a packet sniffer. Wireshark is one of the best ones there is (and free). You can get it from here.

Once installed and running, tell it which network card to sniff and set the filter to port 80 (HTTP). Post whatever form has the data you're after and you'll see the data coming to and from. Look for info beginning with POST in Wireshark. Click on it and you'll see everything that was sent.

[Trilobite]

Originally Posted by Blade

You need a packet sniffer.

Network Analyzer, packet sniffer, Tomatoes, Tomartoes