no may i explain badly...i was meant that i have a crystal report bind to a storeprocedure and of course i have to pass those parameters at runtime so that report will be displayed correctly...

i was passing parameters like this but two of my parameters wereoptional...

string reportpath = Server.MapPath("AssigmntsReport.rpt");
            rpt.Load(reportpath);
            ConnectionInfo connectionInfo = new ConnectionInfo();
            string[] ConnStringKey = ConfigurationManager.AppSettings.GetValues("NestleConnString");
            string ConnStr = ConfigurationManager.ConnectionStrings[ConnStringKey[0]].ConnectionString;
            System.Data.SqlClient.SqlConnectionStringBuilder builder = new System.Data.SqlClient.SqlConnectionStringBuilder(ConnStr);

            rpt.SetDatabaseLogon(builder.UserID, builder.Password, builder.DataSource, builder.InitialCatalog, false);
            rpt.DataSourceConnections[0].SetConnection(builder.DataSource, builder.InitialCatalog, false);
            rpt.DataSourceConnections[0].SetLogon(builder.UserID, builder.Password);

            rpt.SetParameterValue("@Type", Type);

now two of my parameters are optional for my store procedure 

but when was not passing those parameters i was getting error but it get solved now 

 i simply pass null for those parameters.,