private void AddButton_Click(object sender, EventArgs e)
        {
            if (ModulationListBox.SelectedItem == null)
            {
                MessageBox.Show("New channel must have a modulation type.");
                this.DialogResult = DialogResult.None;
                return;
            }

            if (CallsignInput.TextValue == "")
            {
                MessageBox.Show("Channel must have a callsign.");
                this.DialogResult = DialogResult.None;
                return;
            }

            try
            {
                ChannelEditing.AddUserChannelAndMergedChannelInLineup(
                    lineup_, CallsignInput.TextValue,
                    (int)ChannelNumberInput.NumberValue, (int)SubChannelInput.NumberValue,
                    (ModulationListBox.SelectedItem as ModulationTypeWrapper).modulation_type,
                    (int)GuideChannelNumberInput.NumberValue, (int)GuideSubchannelInput.NumberValue,
                    ListingComboBox.SelectedItem as Service);
            }
            catch (Exception exc)
            {
                ExceptionWithKeyValues key_valued_exception = new ExceptionWithKeyValues(exc);
                key_valued_exception.AddKeyValue("lineup", lineup_);
                key_valued_exception.AddKeyValue("Callsign", CallsignInput.TextValue);
                key_valued_exception.AddKeyValue("Subchannel", SubChannelInput.NumberValue);
                key_valued_exception.AddKeyValue("Modulation", ModulationListBox.SelectedItem);
                key_valued_exception.AddKeyValue("GuideNumber", GuideChannelNumberInput.NumberValue);
                key_valued_exception.AddKeyValue("GuideSubChannel", GuideSubchannelInput.NumberValue);
                key_valued_exception.AddKeyValue("Service", ListingComboBox.SelectedItem);
                new ErrorReportingForm("Exception occured when attempting to add a channel", key_valued_exception);
            }
            this.DialogResult = AddButton.DialogResult;
        }