DataTable data = new DataTable();
 private void CreateTable(int RowCount) {
   data = new DataTable();
   data.Clear();
   data.Columns.Clear();
   data.Columns.Add("BillingId");
   data.Columns.Add("Particulars");
   data.Columns.Add("PaymentAmount");
   data.Columns.Add("AllocationBalance", typeof (Decimal));
 }

 private void addDataRow(string paymentType) {
   DataRow newData = data.NewRow();

   newData["BillingId"] = billingId;
   newData["Particulars"] = txtTuitionParticulars.Text;
   newData["PaymentAmount"] = Convert.ToDecimal(txtTuitionAmount.Text);
   data.Rows.Add(newData);
 }