This is not really answering the question because I think AcidHawk is correct. I do suggest, however, that you read this file tutorial mikevanhoff.

Update:
Acidhawk's post above was not there when I wrote this. I was agreeing with his/her post below. But, AcidHawk's post right above mine suggests what you will learn in the link to tachyon's file tutorial in my pre-update post. ++AcidHawk.