// 3) middle: create wxStaticLine with minimum size (3x3)
topsizer->Add(
new wxStaticLine( this, wxID_ANY, wxDefaultPosition, wxSize(3,3), wxHORIZONTAL),
// 3) middle: create wxStaticLine with minimum size (3x3)
topsizer->Add(
new wxStaticLine( this, wxID_ANY, wxDefaultPosition, wxSize(3,3), wxHORIZONTAL),