Quite often, you need to see what a web site is sending from the ASP pages. You could use something like Ethereal but if you are a Firefox fan, an easy way is to use LiveHTTPHeaders.
You can get the LiveHTTPHeaders Firefox extension from here.
Then install it.
Click Firefox Tools / LiveHTTPHeaders.
If you want to limit the URL's that are monitored and you are a dab hand at regular expressions, then click Config tab / Filter URL's with regexp
Close the Config tab
From the Firefox menu, click Select View / Sidebar / LiveHTTPHeaders (or alternatively click Alt L)
Open a page from the website you wish to monitor. What is displayed is what is being sent to the server.