DIM C AS STRING = "Hello World! ", SIZE AS USHORT = LEN(C)
DIM DIRECTION AS BYTE = 0
DIM AS INTEGER X, Y, BTNS
DIM BUTHELD AS BYTE = 0

SCREEN 12

DO
 LOCATE 1, 1
 PRINT C

 GETMOUSE X, Y, , BTNS

 IF BTNS <> 0 THEN
  IF BUTHELD = 0 THEN   'remember if it was pressed, to not react
   BUTHELD = 1          'every frame on the mouse being just held
   IF (X >= 0 AND X < SIZE * 8) AND (Y >= 0 AND Y < 16) THEN
    DIRECTION = 1 - DIRECTION
   END IF
  END IF
 ELSE
  BUTHELD = 0
 END IF

 IF INKEY = CHR(255) + CHR(107) THEN EXIT DO

 IF DIRECTION = 0 THEN
  C = RIGHT(C, 1) + LEFT(C, SIZE - 1)
 ELSE
  C = RIGHT(C, SIZE - 1) + LEFT(C, 1)
 END IF

 SLEEP 100, 1
LOOP