Building Tilesets.
 

I am trying to build a tileset, but everytime it says "cannot open file" error, why is it caused and how do i stop it.

Sounds like a bit format problem. (JCS only wants 8-bit bmps, not 24 bmps that paint produces) Tilesetpal should help you there

....now there is an angry admin to you.

As Puffie said.

And here is some help http://www.jazz2online.com/tilesets/
TilesetPal and other stuff here http://www.jazz2online.com/tilesets/

Also, you can check the site for more info if you wanna.