how to bind Number of months columns automatically using start date and end date

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C#

ASP.NET

SQL-Server-2008R2

i have 3 controls

Number of Months
Start date
End Date

if i give number of months 5 and start date 1/7/2015 then am calculating end date automatically to 1/12/2015 based on (number of months)'

while inserting these values into database i want to bind number of months 5 into 5 columns i.e

jul2015 Aug2015 Sep2015 Oct2015 Nov2015 Dec2015 start date end date

protected void btnSubmit_Click(object sender, EventArgs e)
 {
     SqlCommand cmd = new SqlCommand();
     SqlDataAdapter da = new SqlDataAdapter(cmd);
     cmd.CommandType = CommandType.StoredProcedure;
     cmd.CommandText = "SP_PaymentTracker";
     cmd.Parameters.AddWithValue("@Name", txtName.Text);
     cmd.Parameters.AddWithValue("@InvestmentType", ddlInvestmentType.SelectedItem.ToString());
     cmd.Parameters.AddWithValue("@Amount", ddlAmount.SelectedItem.ToString());
     cmd.Parameters.AddWithValue("@MonthlyPay", txtMonthlyPay.Text);
     cmd.Parameters.AddWithValue("@NumberOfMonths", txtNoOfMonths.Text);
     cmd.Parameters.AddWithValue("@StartDate", txtStartDate.Text);
     cmd.Parameters.AddWithValue("@EndDate", txtEndDate.Text);
     cmd.Parameters.AddWithValue("@Phone", txtMobile.Text);
     cmd.Parameters.AddWithValue("@Address", txtAddress.Text);
     cmd.Connection = con;
     lblmsg.Visible = true;
     lblmsg.Text = "Inserted";
     try
     {
         con.Open();

         cmd.ExecuteNonQuery();
         BindDummyRow();
     }
     catch (Exception ex)
     {
         throw ex;
     }
     finally
     {
         con.Close();
         con.Dispose();
         txtName.Text = ddlInvestmentType.Text = ddlAmount.Text = txtMonthlyPay.Text =
         txtNoOfMonths.Text = txtStartDate.Text = txtEndDate.Text = txtMobile.Text = txtAddress.Text = string.Empty;
     }
 }

 protected void txtStartDate_TextChanged(object sender, EventArgs e)
 {
     string inputString = txtStartDate.Text;
     DateTime dt = DateTime.ParseExact(inputString, "MM/dd/yyyy", CultureInfo.InvariantCulture);
     dt = dt.AddMonths(Convert.ToInt32(txtNoOfMonths.Text));
     txtEndDate.Text = dt.ToString("MM/dd/yyyy");
     txtMobile.Focus();
 }

how to generate number of months columns automatically based on start and end date