Hi Boris,
A couple of things that I think are wrong but I haven't tested them:
- your function doesn't return anything, the last line should be return Var3; instead of HMA = Value3;
- SquareRoot(Period) should be sqrt(Period)
- what's that first line in your function - Vars: Should that be a comment?

I am also learning so if I am not right please someone correct me.

Guiom