Draw a line & erase it

[Ana Gutierrez Pascual <al004180 anubis uji es>]

hi,
I want to know how can I do if after I draw a line, and an event
ocurres, the line will be erase.
there's my code to draw a line.

void DibujarLinea(aplicacion_t *a, linea_t *l)
{
  //reserva un espacio en color map para el color
  gdk_colormap_alloc_color(a->gdkcolormap, &l->lcolor, TRUE, TRUE);
  //esta función pone el color al gdkgc q se va a dibujar
  gdk_gc_set_foreground(a->gdkgc, &l->lcolor);

  gdk_gc_set_line_attributes(a->gdkgc,
                        l->lgrosor,
                        GDK_LINE_SOLID,
                        GDK_CAP_BUTT,
                        GDK_JOIN_MITER);

  gdk_draw_line(a->drawingarea->window, a->gdkgc, l->lx1, l->ly1,
l->lx2, l->ly2);
}

thanks in advance,

ana.