ServerVariables' collection of request objects provides vital information about the client browser, HTTP header, etc. During the development of a web application, we use various variables of this collection to implement, for instance, browser-specific things or things which are specific to certain URLs.
Here is the sample code that can be used to display all the variables in the ServerVariables collection. Normally, I keep such a page in a test folder to test various values that come to the web server in different scenarios.
<%@ LANGUAGE = VBScript %>
<TITLE>List of Server Variables:</TITLE>
<H3>List of Server Variables:</H3>
for each varname in Request.ServerVariables
Response.Write "<TD>" & varname & "</TD><TD>"