Thank you; this seems to solve the problem. I also had an additional problem, which your solution solved "en passant": I didn't like the font used. I think the problem was with diacriticals displayed wrong (DOS/Windows conversion).
Here is your solution, with some further changes made by me:
clear
define window hi from 0,0 to srows()-2, scols()-2 font "Courier"
acti window hi
? "Line 1"
? "Line 2"
acti screen
run del hopefullynonexistentfile.ext
acti window hi
? "Line 3"
Thanks, again.
>Well, I do not know how to resolve it 'naturally'. But here is an alternative solution:
>
>define window hi from 1,1 to 15,15
>acti window hi
>? "Line 1"
>? "Line 2"
>acti screen
>run del hopefullynonexistentfile.ext
>acti window hi
>? "Line 3"
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)