#define inbox(c,mx,my) (mx)>(c.x-c.r) and (mx)<(c.x+c.r) and (my)>(c.y-c.r) and (my)<(c.y+c.r) 

type box
    as integer x,y,r
end type

dim as integer mx,my

screen 19,,2
screenset 1,0
dim as box b1,b2
b1.x=200
b1.y=200
b1.r=50

b2.x=500
b2.y=200
b2.r=50
do
    getmouse mx,my
    cls
    line(b1.x-b1.r,b1.y-b1.r)-(b1.x+b1.r,b1.y+b1.r),3,bf
    line(b2.x-b2.r,b2.y-b2.r)-(b2.x+b2.r,b2.y+b2.r),3,bf
    
    if inbox(b1,mx,my)  or  inbox(b2,mx,my) then 
    beep
    end if
    flip
    sleep 1,1
    loop until len(inkey)