Steps to Pass Parameters to Crystal Reports in C#

//getting and set dataset to report
string sql = "select * from bill_mst";
DataRetriever dr = new DataRetriever();
dr.getValueFromCustomer(sql);
DataTable dtSum = dr.getDataTable();
dsMyReprt k = new dsMyReprt();
k.Tables.Remove("billmst");
dtSum.TableName = "billmst";
k.Tables.Add(dtSum);
CrystalReport1 myDataReport = new CrystalReport1();
//pass parameter
DataSet ds = new DataSet();
// con = new OleDbConnection(ConfigurationManager.ConnectionStrings["connect"].ConnectionString);
OleDbConnection con = Gbl_Cls.conection(); // new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=ClientMgmtDb1.accdb;");
if (con.State == ConnectionState.Closed) con.Open();
OleDbDataAdapter da = new OleDbDataAdapter();
OleDbDataAdapter da1 = new OleDbDataAdapter();
// if(txtbillno.Text.Trim().Length==0)
if (txtbillno.Text != "")
{
    // MessageBox.Show("Enter Bill number");
    da = new OleDbDataAdapter("select ID,NAME,BILL_Number,Date,Address,PO_Number,PO_Date,Narat,Quantity,Rate,Total_price,Vat,Serves_tax,vatAmt,StaxAmt,IncludeTax_AMT,amount,Total_vatAmt,Total_StaxAmt,STax_Amount,VTax_Amount FROM Bill_Mst1 where ID=" + txtbillno.Text.Trim() + "", con);
    da1 = new OleDbDataAdapter("select ID,[BILL_Number],[Narat],[Quantity],[Rate],[Amount],[vatAmt],[StaxAmt] from product_mst where ID=" + txtbillno.Text.Trim() + "", con);
}
da.Fill(ds, "Bill_Mst");
da1.Fill(ds, "Product");
if (ds.Tables.Count > 0)
{
    Bill2 cr = new Bill2();
    CrystalReport1 cr1 = new CrystalReport1();
    cr.SetDataSource(ds);
    cr1.SetDataSource(ds.Tables["Product"]);
    this.crystalReportViewer1.ReportSource = cr;
    this.crystalReportViewer1.Show();
    crystalReportViewer1.Refresh();
}
con.Close();
}
catch (OleDbException s)
{
    MessageBox.Show("Server Problem...");
}

ParameterFields paramFields = new ParameterFields();
// ParameterDiscreteValue paramDiscreteValue = new ParameterDiscreteValue();
ParameterField paramField = new ParameterField();
ParameterDiscreteValue paramDiscreteValue = new ParameterDiscreteValue();
paramField.Name = "@DTotal";
paramDiscreteValue.Value = tot;
paramField.CurrentValues.Add(paramDiscreteValue);
paramFields.Add(paramField);
paramField = new ParameterField();
paramDiscreteValue = new ParameterDiscreteValue();
paramField.Name = "@name";
paramDiscreteValue.Value = name;
paramField.CurrentValues.Add(paramDiscreteValue);
paramFields.Add(paramField);
crystalReportViewer1.ParameterFieldInfo = paramFields;
myDataReport.SetDataSource(k);
crystalReportViewer1.ReportSource = myDataReport;