alists with precomputed variables

[Erik Iverson]

Dear all,

I'm an Elisp beginner, just learning over the last few days. Very naive 
question here, with hopefully a simple answer.

I would like to create an alist where one of the values is something 
that I compute earlier.  Example,

I naively thought that

(setq my-var 20)

(setq my-alist '((p1 . 10) (p2 . my-var)))

would give me

((p1 . 10) (p2 . 20))

, but it instead results in

((p1 . 10) (p2 . my-var))

How can I get what I expected?

If this is a wrong-headed question, please let me know.

Thanks,
Erik