drawing cube on MFC, not smooth :(

Hello,
i'm newbie in openGL

I tried draw cube in MFC using visual studio. when I zoom out the cube, the picture was not smooth

how to solve this problem?
http://i.imgur.com/7aW1x.png?1

http://i.imgur.com/1QzWO.png

thanks in advance

sorry for my bad english

Looks like Z-fighting to me. To prevent that, you have to adjust the range of you Z-Buffer. Especially the near value. (Try to increase it, e.g. double the near value, and check if it gets better.)