private void btnChooseValueset_Click(object sender, EventArgs e)
        {
            ChooseValuset frmValueset = new ChooseValuset();

            frmValueset.SelectedMainTable = _table;
            frmValueset.SelectedContent   = (PxContent)lbContents.SelectedItem;
            frmValueset.SelectedVariable  = (PxVariable)lbVariables.SelectedItem;
            frmValueset.selectedValueset  = valueSetLabel1.Text;
            frmValueset.selectedValuePool = VariableFacade.GetValuepoolByValueSet(valueSetLabel1.Text);
            frmValueset.FootnoteNo        = FootnoteNo;
            if (frmValueset.ShowDialog() == System.Windows.Forms.DialogResult.OK)
            {
                FootnoteNo = frmValueset.FootnoteNo;
                ((PxVariable)pxVariableBindingSource.DataSource).ValueSet = frmValueset.selectedValueset;
                ((PxVariable)pxVariableBindingSource.DataSource).MarkAsDirty();
                _table.MarkAsDirty();
            }
        }