openfiledialog^ dlgopenfile = gcnew openfiledialog ();
string^ filename;
dlgopenfile->initialdirectory = "d:\\";
dlgopenfile->filter = "txt files (*.txt)|*.txt|all files (*.*)|*.*";
dlgopenfile->filterindex = 1;
dlgopenfile->restoredirectory = true ;
dlgopenfile->showdialog();
filename = dlgopenfile->filename;
tb_path->text = filename;