New Post: Check for row existence

Hi, i need to check existence of the row.
For example, this code in NPOI.Examples (SetBordersOfRegion)

//create horizontal 1-9
            for (int i = 1; i <= 9; i++)
            {
                sheet1.CreateRow(0).CreateCell(i).SetCellValue(i);
            }

every time create a new row.
result:
9
instead of
1 2 3 4 5 6 7 8 9