Why declare colours(2) and chk(2)???
You’re only using 2 elements in both. You know arrays are zero based, but you need to declare arrays with the Upperbound and not the Length...
I.e. colours(1), chk(1)
Oh !
I've always used length, maybe from my original BASIC language from the 1970's.
Poppa
Along with the sunshine there has to be a little rain sometime.