Parol evidence is admissible to show that a writing was originally void or has subsequently become so. (Code 1907, §3963; Code 1923, §7659; Code 1940, T. 7, §371.)
Parol to Show Writing Void
Ala. Code § 12-21-33, under Competency and Admissibility.
Ala. Code § 12-21-33