ASP.NET执行存储过程，并获取存储过程的返回值

//连接数据库
        string myStr = CODE.DbHelperSQL.connectionString;
        SqlConnection myConn = new SqlConnection(myStr);
        myConn.Open();
        //创建SqlCommand对象
        SqlCommand cmd = new SqlCommand("pr_GetSQLWhere", myConn);
        cmd.CommandType = CommandType.StoredProcedure;
        //添加参数
        SqlParameter sUserID = cmd.Parameters.Add("@sUserID", SqlDbType.VarChar,50);
        sUserID.Value ="01";
        SqlParameter sRetSQL = cmd.Parameters.Add("@sRetSQL", SqlDbType.VarChar,50);
        sRetSQL.Direction = ParameterDirection.Output;
        cmd.ExecuteNonQuery();
        string strs = sRetSQL.Value.ToString();
        return strs;