Need Firefox plug-in to show POSTed variables

I need to find out what vari开发者_如何学运维ables and values are being POSTed to a script that I'm debugging. It's doing something strange to them, and it needs to start a session so I can't ouput them right at the beginning. I'm hoping to find a plug-in for Firefox that will show me what they are directly from the browser. Does anyone know of such a thing?

Use Firebug. It's awesome.

The Net panel shows you what's going on over HTTP.

Live HTTP Headers

Let's you see every request, edit it and replay it. Excelent plugin and easy to use...

Firebug does that perfectly :)

1. install Firebug
2. open the network tab

Fiddler has such a plugin and it is also just a good HTTP debugger in general

LiveHTTPHeaders is an oldie but a goodie