Need help to get the name of a class at runtime

[Bilo]

I have a Class MediaDriver which plays audio and video using MDirectX.
The Application Window is in another Class (MainGUI) which sends their
trackbar and class objects to the
MediaDriver class.
MediaDriver will be a DLL. And there is the problem. What when the calling
class' s name is not MainGUI?
Is there a way to do this
declare maingui as a type of a class (the compiler know that it will be a
class)
and when I do
this.maingui = maingui , than it knows which class it is

public class MediaDriver
{
.....
private MainGUI maingui;
Label label1;
.....

public MediaDriver(TrackBar trackBar1 , MainGUI maingui)
{
.....
this.maingui = maingui;
.....
}
}