unable to copy file "obj\Debug\Project1.exe" to "bin\Debug\Project1.exe".The process

Question

Hi,
I have started one new project , and I have added few forms , after I have run the project it is showing some error like "unable to copy file "obj\Debug\Project1.exe" to "bin\Debug\Project1.exe".The process
cannot access the file "bin\Debug\Project1.exe"because it is being used by another process."
Can anyone tell how I can come out of this problem

Thanks in Advance
Audi