How can I pass the number (short type in C#) to the parameter of Stored procedure in Crystal report?

I want to generate a report with C# and Crystal Report.

in Crystal report, the data  come from a stored procedure with parameter, there is a number parameter named @type, the valued was assigned form C# code:

    discretevalue1 = new ParameterDiscreteValue();

    discretevalue1.Value = "1";

    ParameterValues values1 = new ParameterValues();

    values1.Add(discretevalue1);

    this.objRpt.DataDefinition.ParameterFields["@Type"].ApplyCurrentValues(values);

in Stored Procedure,  the parameter was declared as:

Create PROCEDURE SP(@Type smallint) as ...

    IF (@Type=1)

    Begin

        //doit

    end

...

if I commented the line in SP: IF (@Type=1), the statement in doit could be executed successfully, I could see the correct data on the report. but if I did not commented the this line, the statement in doit would be executed, no data would be appeared on the report.

run the SP in SQL server: EXEC SP 1  will get the correct result.

I do not know what caused this issue. Could someone tell me how can I pass the number parameter to Stored Procedure in Crystal report?

Thanks for any help