Running sum of only Previous and Current Month

[Anonymous]

Hi,

Following Data set :

Dimension	Month	Amount
B1	Jun	5
	July	6
	August	15
	September	12
	October	18
	November	2
	December	6
B2	Jun	24
	July	0
	August	21
	September	9
	October	56
	November	41
	December	20

what i want is to add previous Amount values in the current month and show zero values in the previous month.

Like for Example For Dimension B1 :

Current Month August 

it should show 15+6+5 = 26 instead of 15 , and show zero values in Jun and July.

What i was doing in the script

IF(Month(Date#(Month_field,'YYYYMMDD'))=Month(Today()),Previous(Rangesum((Amount))),Amount) AS Amount,

the issue is, its range sum the very previous record in the field but not all the values.

like for B1 Dimension for August i got the value 21 instead of 26

and in B2  Dimension for August i got the value 21 as the very previous record is 0.

is there any way we can add the all the previous amount values into one.

Thanks

[sunny_talwar]

Difficult to say what might be the issue. Would you be able to share a sample where you see the issue?