private void newmoleculebutton_Click(object sender, EventArgs e) { openFileDialog1.DefaultExt = "pdb"; openFileDialog1.Filter = "PDB files (*.pdb)|*.pdb|All files (*.*)|*.*"; openFileDialog1.FileName = ""; openFileDialog1.CheckFileExists = true; DialogResult dr = openFileDialog1.ShowDialog(); if (dr == DialogResult.OK) { foreach (String filename in openFileDialog1.FileNames) { Molecule m1 = new Molecule(filename); if (m1.Error.Length > 0) { MessageBox.Show("Unable to load " + filename + ": " + m1.Error, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); continue; } _molecules.Add(m1); this.moleculescomboBox.Items.Add(m1.Name); } } if (moleculescomboBox.Items.Count > 0) { moleculescomboBox.SelectedIndex = moleculescomboBox.Items.Count - 1; calculatebutton.Enabled = true; } }