Restricting CPU Usage

Hi, I''m writing a CPU-hungry simulation in C# and I''d like to add a slider bar that lets the user adjust how much of the CPU the simulation can use. So for example I could set it to 60% and never have my program''s CPU usage go above 60%. I''ve noticed that other simulation programs (like folding@home) have this option. How can I accomplish this? Is it an API call? Or do I have to have my program constantly monitor it''s usage and Sleep() when it is too high? ---------------------------------------- Let be be finale of seem, seems to me. ---------------------------------------- Coding: http://www.stanford.edu/~jjshed/coding Miscellany: http://www.stanford.edu/~jjshed