DEFINE INPUT PARAMETER custNum AS INTEGER NO-UNDO.
...

FUNCTION GetTotalOrdersByNumber RETURNS INTEGER (threshold AS DECIMAL): 
...
END.
...

namespace BigOrderInfoClient  {

  using Progress.Open4GL;
  using Progress.Open4GL.Proxy;

  public class samplecode         {
    public static void PersistentProcedure( )  {
      // Connect to the application server
      Connection myConn = new Connection
                          ("http://host:portnumber/apsv", "", "", "");
      OpenAppObject openAO = new OpenAppObject(myConn, "mySvc");

      // Run the persistent procedure
      // First set up parameters
      ParamArray parms = new ParamArray(1);
      System.Int32 custNum = 3;

      // Set up input parameters
      parms.AddInteger(0, custNum, ParamArrayMode.INPUT);
      // Run procedure
      OpenProcObject openPO = openAO.CreatePO("OrderInfo/CustomerOrder.p", 
                                              parms);

      // Call UDF
      // First set up parameters
      System.Decimal retVal;
      int Threshold = 1000;
      parms.Clear( ); // Clear ParamArray for next call

      // Set up input parameters
      parms.AddDecimal(0, Threshold, ParamArrayMode.INPUT);

      // Set up return type
      parms.ReturnType = Parameter.PRO_DECIMAL;

      // Run procedure
      openPO.RunProc("GetTotalOrdersByNumber", parms);

      // Get return value
      retVal = (System.Decimal)parms.ReturnValue;

      openPO.Dispose( );
      openAO.Dispose( );
    }
  }
}