I have some data for each month.say no of transactions for each month.When users selects any two months(from month,to_month) ..trend analysis to
be shown with respect to from_month.i.e if from month is march2012 and to month is june 2012 then variation sud be as 
month variation
march
-
april (data for april-data for march)/data for march *100
may (data for may-data for march)/data for march *100
june (data for june-data for
march)/data for march *100

is there any way to do so in pivot table.

I have some data for each month.say
no of transactions for each month.When
users selects any two months(from
month,to_month) ..trend analysis to
be shown with respect to from_month.i.e
if from month is march2012 and to month
is june 2012 then variation sud be as

month variation
march
-
april (data for april-data for
march)/data for march *100
may (data
for may-data for march)/data for march
*100
june (data for june-data for
march)/data for march *100

is there
any way to do so in pivot table.