Sql server 2005 使用sql server 2005进行月累计和

我的表格中有如下数据：

> HourWork  MonthName
> 
> 366.00    May 2010    
> 1000.00   Sep 2010    
> 1704.00   Oct 2010    
> 3000.00   Nov 2010

现在，我想制作一个存储过程来获得以下结果：

> HourWork  MonthName
> 
> 366.00    May 2010    
> 1366.00   Sep 2010    
> 2704.00   Oct 2010    
> 4704.00   Nov 2010

意味着获取下个月的值，以及当前月份的数据

任何人都可以告诉我如何使用存储过程得到这样的结果

CREATE TABLE WorkTimeLog
(
    WTLID       int identity    NOT NULL,
    HourWork    numeric(7,2)    NOT NULL,
    MonthStart  datetime        NOT NULL,
    PRIMARY KEY(WTLID)
)
go

set dateformat dmy;

insert WorkTimeLog values (366.00,  '01-May-2010')
insert WorkTimeLog values (1000.00, '01-Sep-2010')
insert WorkTimeLog values (1704.00, '01-Oct-2010')
insert WorkTimeLog values (3000.00, '01-Nov-2010');
go

select  IsNull((select HourWork from WorkTimeLog where MonthStart = wtl.MonthStart) + (select HourWork from WorkTimeLog where MonthStart = (select MAX(MonthStart) from WorkTimeLog where MonthStart < wtl.MonthStart)), wtl.HourWork) as PairTotal,
        RIGHT(CONVERT(char(11), wtl.MonthStart, 13), 8) as Period
from    WorkTimeLog as wtl 
order   by wtl.MonthStart
go

PairTotal   Period
366.00     May 2010
1366.00   Sep 2010
2704.00   Oct 2010
4704.00   Nov 2010