CreateCanvas in Blitz3D

Hello,
is there any one who can help me with a function in
---BLITZ3d-- not BLITZ PLUS
I need help with
CreateCanvas (0, 0, x, y, Parent)
CreateWindow("Name", ClientWidth(Desktop())......
canvasbuffer

are there any functions or decls? like this in BLITZ3D (not Blitz+)

Graphics GfxWidth(), GfxHeight(), 0, 1

or

Graphics GfxWidth(), GfxHeight(), 0, 2

thanx Mr. WolRon
Nice, but for what? whats about read out the clientwidth of a Desktopwindow? Graphics is not Canvas, whats about the position? I belive it's not that easy.