User chooses which file to open

[Clippy]

Sure just use a string variable like FileName$ in the open statement instead of a literal value.

Create a menu display for the user and use SELECT CASE:

Code:

DO: choice$ = INKEY$ : LOOP UNTIL choice$ <> ""

SELECT CASE choice$
         CASE "1": Filename$ = "ABCD.txt"
         CASE "2": Filename$ = "EFGH.txt"
END SELECT

Then open the file: OPEN Filename$ FOR INPUT AS #1