View.Set ("graphics:max,max")

proc ripple(x,y,numRings:int)
    for i:1 .. numRings
        drawoval (x,y,i*10,i*10,120)
    end for
end ripple

var mx,my,mb:int

loop
    mousewhere(mx,my,mb)
    if mb = 1 then
        ripple (mx,my,10)
    end if
end loop

ripple(maxx div 2,maxy div 2, 10)