[luatex] Absolute beginners questions

[Keith J. Schultz]

Hi All,

I am just beginning to switch to Lua(la)Tex.

I find it hard to find in-depth documentation for luatex.

So here my questions:
	1) As I understand it I can inject tex-code back to tex via texsprint, inside of 
	    a directly call.
	2) Is it possible to access and or manipulate tex-variable macros directly?
	3) Is it possible to to save globals between directly calls?

Any help and reference to documentation would be gladly appreciated.

Many Thanx in advance

regards
	Keith.