How do I load a .png graphic file into a dialog in Irix?

[motif]

Im try to load a .png file in Irix,. Im habe to load it, he program don't
display it.
whats the problem?

where a bit of my code.

void CBaseDialog::LoadBitmap(wxString bitmapname,unsigned int nbcontrol)
 {
 #if wxUSE_LIBPNG
  wxImage::AddHandler( new wxPNGHandler );
 #endif

  wxBitmap bit;
  if (bit.LoadFile(bitmapname,wxBITMAP_TYPE_PNG))
  {
   //wxMessageBox(bitmapname,"Quit setup?", wxICON_EXCLAMATION | wxYES_NO |
wxYES_DEFAULT , NULL);
   wxStaticBitmap* bitmap =
static_cast<wxStaticBitmap*>(GetDlgItem(m_BaseDialog,nbcontrol));
   bitmap->SetBitmap(bit);
  }
 }