Using Request and the tracing method in a function

I'm using page tracing method and instead of writing it over and over, I wanted to write a function in a .cs page and just call the function from my other pages. Here is my code: public void pageTracing() { if (Request["trace"] == "trace") { Trace.isEnabled = true; } } It's giving me these errors: The name 'Request' does not exist in the class or namespace 'web_isotope.functions.clsFunctions' The type or namespace name 'Trace' could not be found (are you missing a using directive or an assembly reference?) If you please could, give me an example of the correct way to do this, I'm just beginning, thanks in advance!