CONTROLLER MOUSE OPEN 2, lbutton
GUI CURSOR ON
GUI CURSOR SHOW
settick 16,mousemove
do:loop
sub mousemove
 gui cursor mouse(X,2),mouse(Y,2)
end sub
sub lbutton
' whatever
end sub

mouse_present = MOUSE(TEST)

If mouse_present then MOUSE ON, <mouse_interrupt_routine>
'   (we need to do this as there may not be a mouse present. Turns on cursor.)

do
 whatever it is that programs do
 Select Case b
 Case 1
   left button action : b=0
 Case 2
   middle button action : b=0
 Case 3
   right button action : b=0
 End Select
loop until fed up

MOUSE OFF
'  (turns off mouse interrupt and cursor)

do something else entirely

MOUSE ON, <mouse_interrupt_routine>  - (no real need to test if mouse present now)

... and carry on

End

Sub <mouse_interrupt_routine>
 x = MOUSE(X)
 y = MOUSE(Y)
 b = MOUSE(BUTTON) - (returns 1,2 or 3. scroll is ignored)
End Sub

CONTROLLER MOUSE OPEN [n] [,LBinterrupt [,RBinterrupt [,LBUPinterrupt]]]