i am trying to create a forumla which will work out if Total Km Travelled is greater then the previous value on the date before. I am grouping by Bike Rider ID.

 

e.g

date      km Travelled

1/5/12        20

4/5/12        30

3/6/12        17

4/6/12         5

6/6 /12       20

 

Basically i want the report to highlight the value in RED if tis less than the prvious.

 

I have tried a few things, for example

 

if (kmtravelled) <= previous(kmtravelled) then

crRed else

crBlack

 

the issue is, its not working it out by group, so the last value 6/6/12 , 20  sometimes highlights red as it then compared to the value from the next riders ID...

 

any advice?

 

should i be doing this in a cross tab?