Cannot find column 25 Exception coming - ms-access-2007

Question

I am creating one report where data exported from my access database to excel here. I'm not using any datagridview , when user click one checkbox appropriate report he can able to download for this I have written code but when I run this code its giving me Cannot find column 25, I don't know why its showing me this?
In access table I have total 25 column :
string sql = null;
string data = null;
int i = 0;
int j = 0;
Excel.Application xlApp;
Excel.Workbook xlWorkBook;
Excel.Worksheet xlWorkSheet;
object misValue = System.Reflection.Missing.Value;
xlApp = new Excel.Application();
xlWorkBook = xlApp.Workbooks.Add(misValue);
xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);
string connectionString = null;
connectionString = ConfigurationManager.ConnectionStrings["AccessConnectionString"].ConnectionString;
cnn.ConnectionString = connectionString;
cnn.Open();
sql = "SELECT * FROM Billing WHERE Bill_No and Bill_Date is null order by FormNo desc";
OleDbDataAdapter dscmd = new OleDbDataAdapter(sql, cnn);
DataSet ds = new DataSet();
dscmd.Fill(ds);
cnn.Close();
for (j = 0; i < ds.Tables[0].Columns.Count; j++)
{
xlWorkSheet.Cells[1, j + 1] = ds.Tables[0].Columns[j].Caption; // Exception coming this line
}
for (i = 0; i < ds.Tables[0].Rows.Count; i++)
{
for (j = 0; j < ds.Tables[0].Columns.Count; j++)
{
data = ds.Tables[0].Rows[i].ItemArray[j].ToString();
xlWorkSheet.Cells[i + 2, j + 1] = data;
}
}
System.Windows.Forms.SaveFileDialog saveDlg = new System.Windows.Forms.SaveFileDialog();
saveDlg.InitialDirectory = #"C:\";
saveDlg.Filter = "Excel files (*.xls)|*.xls";
saveDlg.FilterIndex = 0;
saveDlg.RestoreDirectory = true;
saveDlg.Title = "Export Excel File To";
xlWorkBook.Close(true, misValue, misValue);
MessageBox.Show("File Downloaded successfully...");
xlApp.Quit();
}

Answer 1

i got the answer here i change my for loop
for (i = 0; i <= ds.Tables[0].Rows.Count - 1; i++)
{
for (j = 0; j <= ds.Tables[0].Columns.Count - 1; j++)
{
xlWorkSheet.Cells[1, j + 1] = ds.Tables[0].Columns[j].Caption;
data = ds.Tables[0].Rows[i].ItemArray[j].ToString();
xlWorkSheet.Cells[i + 2, j + 1] = data;
}
}