Fl_Roller(int X, int Y, int W, int H, const char *L=0);

function Create
       (X, Y, W, H : in Integer;
        Text       : in String)
    return Roller;

void draw();

procedure Draw
       (This : in out Roller);

int handle(int);

function Handle
       (This  : in out Roller;
        Event : in     Event_Kind)
    return Event_Outcome;