private void comboBoxSorceName_SelectedIndexChanged(object sender, EventArgs e)
 {
     try
     {
         sourceControl = new SourceControl();
         string sourceName = comboBoxSorceName.Text;
         string address    = sourceControl.getSourceAddress(sourceName);
         string employee1  = sourceControl.getSourceEmployee1(sourceName);
         string employee2  = sourceControl.getSourceEmployee2(sourceName);
         string phone1     = sourceControl.getSourcePhone1(sourceName);
         string phone2     = sourceControl.getSourcePhone2(sourceName);
         string phone3     = sourceControl.getSourcePhone3(sourceName);
         txtSourceName.Text      = sourceName;
         txtSourceAddress.Text   = address;
         txtSourceEmployee1.Text = employee1;
         txtSourceEmployee2.Text = employee2;
         txtSourcePhone1.Text    = phone1;
         txtSourcePhone2.Text    = phone2;
         txtSourcePhone3.Text    = phone3;
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message);
     }
 }