var_DelCallback( p_dec, "vbi-position", Position, p_sys );
var_DelCallback( p_dec, "vbi-opaque", Opaque, p_sys );
var_DelCallback( p_dec, "vbi-page", RequestPage, p_sys );
var_DelCallback( p_dec, "vbi-position", Position, p_sys );
var_DelCallback( p_dec, "vbi-opaque", Opaque, p_sys );
var_DelCallback( p_dec, "vbi-page", RequestPage, p_sys );