if (input in ['Y', 'y']) then WriteLn('blah blah') else if (input in ['N', 'n']) then WriteLn('blah') else WriteLn('Input invalid');
if (LowerCase(input) = 'y') then WriteLn('blah blah') else if (LowerCase(input) = 'n') then WriteLn('blah') else WriteLn('Input invalid');