private void dialogKapaniyor(object sender, FormClosingEventArgs e)
 {
     populateList(comboBox1.SelectedIndex);
     dialog = null;
 }
 private void button1_Click(object sender, EventArgs e)
 {
     dialog              = new alim_dialog();
     dialog.FormClosing += new FormClosingEventHandler(dialogKapaniyor);
     dialog.ShowDialog();
 }