ASP.Net: Enabling Tracing

We can enable tracing at page level or at application level using the following.
<@Page Trace="True" %>

Also we can do Trace.Write("Hi can you read this fails at line 100");

It is helpful for debugging

Also you can trap events like page load using,
Trace.Warn("Page_Load","The page has loaded what do you want me to do next !!!");