C#

...
     foreach (Label lb in FlowLayoutPanel1.Controls)
                            {
                                lb.MouseDoubleClick+=new MouseEventHandler(lb_MouseDoubleClick);
                            }
    ...
    private void lb_MouseDoubleClick(object sender, MouseEventArgs e)
            {
                NewForm form = new NewForm();
                form.ShowDialog();
                ((Label)sender).Text = ...;//I want get text from TextBox of the NewForm here
            }

private void llenarElementos()
        {

            cbo_codsim.Items.Clear();


            int filascod = base_Gps_InfoDataSet.Tables["SIM"].Rows.Count;

            for (int y = 0; y < filascod; y++)
            {
                cbo_codsim.Items.Add(base_Gps_InfoDataSet.Tables["SIM"].Rows[y][1].ToString());
            }

        }