ASP.NET introduces new functionality that allows you to view diagnostic information about a single request for an ASP.NET page simply by enabling it for your page or application. Called tracing, this feature also allows you to write debug statements directly in your code without having to remove them from your application when it is deployed to production servers. You can write variables or structures in a page, assert whether a condition is met, or simply trace through the execution path of your page or application.
One interesting feature comes built in with .Net Framework is : Trace Viewer.
To Test this functinoality you have to enable tracing in your application. Change <Trace> element in the Web.Config as follows :
<trace enabled=”true” requestLimit=”10″ pageOutput=”false” traceMode=”SortByTime” localOnly=”true” />
Once you have enabled tracing for your application, each page in the application will execute any trace statements that it contains when it is requested. You can view these statements and the additional trace information in the trace viewer by requesting Trace.axd from the root of your application directory.
Note When you enable tracing for an application, you can view the trace statements, and additional information, in any page in the application by setting the pageOutput attribute to true in the Web.config file.The trace viewer allows you to choose a specific request from the pages that have been requested from your application.
Well, if you are still using Classic ASP, than here is a similar utility for you. Click Here download.