var cellType1 = new GC.Spread.Sheets.CellTypes.CheckBox();
cellType1.caption("caption");
cellType1.textTrue("true");
cellType1.textFalse("false");
cellType1.textIndeterminate("indeterminate");
cellType1.textAlign(GC.Spread.Sheets.CellTypes.CheckBoxTextAlign.bottom);
cellType1.isThreeState(true);
activeSheet.getCell(1, 1).cellType(cellType1);