checking bitmap on button

I am working with visual c++,i am using three buttons and i have inserted bitmap on one button.When i click only one button the bitmaps get hide and buttons chage their postion.Now when user clicks on any button it should tell that whether bitmap is present on that button or not??Which condition should i use or which function to use???Any kind of help will be appreciated

Why not just move the bitmap instead? Have a variable to hold the current position of the bitmap (1,2,or 3).