private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {
                 // Stream^ myStream;
                 System::IO::Stream ^ myStream;
      OpenFileDialog^ openFileDialog1 = gcnew OpenFileDialog;
      

     
      openFileDialog1->InitialDirectory = "c:\\";
      openFileDialog1->Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*";
      openFileDialog1->FilterIndex = 2;
      openFileDialog1->RestoreDirectory = true;
     // openFileDialog1->ShowDialog();
    
      if ( openFileDialog1->ShowDialog() == System::Windows::Forms::DialogResult::OK )
      {
         if ( (myStream = openFileDialog1->OpenFile()) != nullptr )
         {
              system("c:\\WinDjView.exe c:\\pascal.djvu");
            
            myStream->Close();
         };
      
      };
             }    ;
     
             };

 if ( somefile == ".djvu") system(" c:\\WinDjView.exe somefile");