Crystal reportviewer ask to enter parameters when click Next

Crystal reportviewer ask to enter parameters when click Next page,Export and print button.How to solved the problem.I will tried solved the problem long time.Please,help

Bellow is my code.

 

void DisplayReport()
{
crypt.Load(Server.MapPath("DetailsRpt.rpt"));
SqlDataAdapter sda = new SqlDataAdapter("RptDetails", con);
sda.SelectCommand.CommandType = CommandType.StoredProcedure;
sda.SelectCommand.Parameters.Add("@User", System.Data.SqlDbType.VarChar, 100).Value = lblUser.Text;
sda.SelectCommand.Parameters.Add("@Date1", System.Data.SqlDbType.VarChar, 100).Value = datepicker.Text;
sda.SelectCommand.Parameters.Add("@Date2", System.Data.SqlDbType.VarChar, 100).Value = datepicker2.Text;
DataTable dt = new DataTable();
sda.Fill(dt);
crypt.SetDataSource(dt);
Reportviewer.ReportSource = crypt;
}