How to stop all sound in a C# program

Hi all,
Now I am programing a game in C#. So I use many sound events (moving, punching, screaming...). I create a Mute button, when running program. when users click on Mute, all sound will be disabled. So, i want use a system call from thread library, some thing like that...I have searched in MSDN but no feasible result. Somebody answer me, please. Many thanks!