delphi adodataset1 调用存储过程的方法

CREATE   PROCEDURE  adddata
@name nvarchar(20) ,
@mm nvarchar(20) ,
@ddd nvarchar(30),
@rdata nvarchar(30)
AS
INSERT INTO table (name,mm,ddd) 
     VALUES (@name,@mm,@ddd)
set @redata='操作成功';
select @redata as redata
return 1
GO

procedure TForm1.BitBtn1Click(Sender: TObject);
var
tstr:string;
begin
tstr:='123';
ADODataSet1.Close;
ADODataSet1.CommandText:='adddata a,a,a,'+tstr;//此处写存储过程
showmessage(ADODataSet1.CommandText);
ADODataSet1.Open;
showmessage(ADODataSet1.FieldByName('redata').AsString);//此处是返回值
end;