Hi,
What you need to do is define a screen with a backbuffer something like this;
SetGraphicsDriver GLMax2DDriver()
Const xres = 1024
Const yres = 768
Graphics xres,yres,32,60,GRAPHICS_BACKBUFFER
Then all drawing by default is on the back buffer, you just need to use this command in your main loop to swap the buffers;
Flip(-1)
Hopt that helps!