private void OpenFile() { var openFileDialog = new OpenFileDialog { InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Personal), Filter = "Text Files (*.txt)|*.txt|All Files (*.*)|*.*", CheckFileExists = true, Multiselect = true }; if (openFileDialog.ShowDialog(this) == DialogResult.OK) { foreach (var fileName in openFileDialog.FileNames) { var form = new NoteForm { MdiParent = this, FileName = fileName }; form.LoadDocument(); form.Show(); } } }