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?

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Use Firebug. It's awesome.

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

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Live HTTP Headers

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

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Firebug does that perfectly :)

1. install Firebug
2. open the network tab

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

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LiveHTTPHeaders is an oldie but a goodie