If you don't understand how to do this, the best way to learn is to do this manually while watching what happens with FireBug (on Firefox) or the equivalent tools for IE, Chrome or Safari.
You must duplicate in your code whatever happens in the protocol when the user accepts the terms & conditions manually.
You must also be aware that the UI presented to the user may not be sent directly as HTML, it may be constructed dynamically by Javascript that would normally run on the browser. If you are not prepared to fully emulate a browser to the point of maintaining a DOM and executing Javascript, then this may not be possible.