How to pass values to crystal report field ?

[hdv212]

Hi i have a simple unBound field in my report designer named 'UnboundString1'. i want to pass value to this field froom code, but i don't know how to do that. i also create a parameterField and use this code to pass value but nothing happened :

this.customersTableAdapter.Fill(this.northwindDataSet.Customers);

        ParameterField myParam = new ParameterField();
        myParam.ParameterFieldName = "UnboundString1";
        ParameterDiscreteValue myDiscreteValue = new ParameterDiscreteValue();
        myDiscreteValue.Value = "USA";
        myParam.CurrentValues.Add(myDiscreteValue);
        this.crystalReportViewer1.ParameterFieldInfo.Add(myParam);

        this.CustomersReport1.SetDataSource((DataTable)this.northwindDataSet.Customers);
        this.CustomersReport1.Refresh();
        this.crystalReportViewer1.RefreshReport();

how to workaround this problem ?