测试数据库链接
        public  bool TestDBConnect( strDSN)
        {
            bool bReturn = true;
            SqlConnection oSqlConnection =  SqlConnection(strDSN);
             iTmp = oSqlConnection.ConnectionTimeout;
            try
            {
                oSqlConnection.Open;                
            }
            catch
            {
                bReturn = false;
            }
            finally
            {
                oSqlConnection.Close;
                oSqlConnection.Dispose;
            }
             bReturn;
        }