A "proper" fire effect

This code generates a fire effect following a well known algorithm that I certainly didn't come up with :) I'm surprised few people submitted some fire effects which, I'm sorry to say, didn't look all that neat. I have to give them credit for trying to be original though, unlike me! Note that I did all I could to make the code as efficient as possible. In the code, I explained the shortcuts I used compared to what could lead to more a realistic effect if you are ready to sacrifice a wee bit of performance. I do NOT use any controls, especially not a picture box! Yuk! Please don't! And I also use backbuffering to prevent flickering. Finally, MAKE SURE TO COMPILE IT! If you run it from VB, it will be slow as it will be interpreted. Cheers gals and guys, hope you like it :) PS: I rated it as "intermediate" only because of the use of a couple of APIs, but beginners should see that it's actually very simple! UPDATE: duh, I learnt to do a proper 256 colours GIF, it looks better. UPDATE2: duh, I also learnt to read and use a keyboard.