Crystal Reports RunningMax Amount for a 4 week Interval

Message

     Hi,

I need to display a RunningMax Trendline in a chart for a four week interval. This report is grouped on weeks (report date).

Here's how the data looks like :-

Report Date   Amount
------------+----------
03/01/2008      2000
03/09/2008        50
03/16/2008       100
03/16/2008       200
03/23/2008       500
03/23/2008       700
03/30/2008       350       
04/06/2008      1500

Desired Output is :-

Report Date   Amount   RunningMax
------------+--------+------------
03/01/2008      2000           0
03/09/2008        50           0
03/16/2008       300           0
03/23/2008      1200        2000 (max amount between 3/1 to 3/23)
03/30/2008       350        1200 (max amount between 3/9 to 3/30)
04/06/2008      1500        1500 (max amount between 3/16 to 4/6)