' mouse demo
FOR i%=0 TO 20
  BOX 50+i%*20,100,66+i%*20,140
  TEXT 50+i%*20+4,130,CHR$(i%+65)
NEXT i%
GET 51,101,65,139,x$
MID$(x$,7)=STRING$(LEN(x$),255)
oi%=-9
DO
  MOUSE x%,y%,k%
  IF k%
    IF y%>100 AND y%<140
      IF x%>50 AND x%<66+20*20
        i%=(x%-50)/20
        IF i%<>oi%
          PUT 51+oi%*20,101,x$,6
          oi%=i%
          PUT 51+i%*20,101,x$,6
        ENDIF
      ENDIF
    ENDIF
  ENDIF
LOOP