Force Timeout In .cs File?

I have a web application with many .cs files.

In one of the .cs file (lets say MyCode.cs) there a function (lets say MyFunction)

function MyFunction()
{
//line 1
//line 2
//line 3
}

Now, sometimes line 2 and line 3 takes about a minute to run/timeout (in rare case when some other system is offline).

Without changing the timeout values of the rest of the application or page is it possible to do something that throws an exception if line 2 and line 3 are not finished running within 15 seconds?