display images randomly

Hey guys, am using opengl with borland c++, and i want to display images randomly. i.e: I wrote 5 functions , each of which create polygons like cicle, square, etc. And i have tried to call these functions one after the other but only the first image is displayed on the screen(may be this is case of mainloop()). What i want is:
one image should be displayed randomly first ,then it waits for 1 minute on the screen and the second image will be displayed(i.e so that the first will be destroyed)…

If you use depth testing, you should clean depth before drawing something new.

Ok, What do u advice me to create ,lets say 5 images, and display them one after the other randomly. I mean what concepts( like function,etc.)should i have to read and use?