ultragrid checkbox

cols["checked"].Header.Caption = "";
cols["checked"].Header.ToolTipText = "Download DataBase";
cols["checked"].Width = 20;
cols["checked"].Header.CheckBoxVisibility = HeaderCheckBoxVisibility.WhenUsingCheckEditor;
cols["checked"].CellActivation = Activation.AllowEdit;
cols["checked"].CellClickAction = CellClickAction.Edit;
cols["checked"].Style = Infragistics.Win.UltraWinGrid.ColumnStyle.CheckBox;
uGridServer.DisplayLayout.Bands[0].Columns["checked"].Header.CheckBoxSynchronization = HeaderCheckBoxSynchronization.RowsCollection;

uGridServer.DisplayLayout.Override.AllowUpdate = DefaultableBoolean.True;