Quick (hopefully!) question about Texturing Cubes

Blitz3D Forums/Blitz3D Beginners Area/Quick (hopefully!) question about Texturing Cubes

Hi, I'm currently working on learning about vertexes and surfaces, so I've been trying to work out exactly what the code posted here does, and how it works. Unfortunatly it doesn't actually seem to work, any time I run it in blitz3d I get a memory acess violation at the

UpdateNormals m

when I put a ; in front of it, I instead get the error at my RenderWorld() in the rendering loop.

Can someone fix it / tell me what's wrong with the above code so I can continue trying to use it to learn what I'm doing?