How to detect a missing month in script

[canmarroig]

I've a problem i'd like you to help me to solve: i've 3 different sources to use to import data:

- an excel for the current month: A.xls

- 12 file for the previous 12 months: yearmonth_B.xls

- in case of lack of the previous month, i've a further excel file. C.xls

For instance: today my A file is 201410.xls, if I can't find B file 201409.xls 'ive to use C.xls

I've created 2 variables:

let vMonthMax=peek('Month',0,tmp)

let vMonthPrec=peek('Month_prec',0,tmp)

but i've no idea how to put the condition to check if there is file B. Can you help me?

Tks

[#2]

Hi

you can use the below.

if  isnull(FileTime($(vMonthPrec) & '.xls')) then

     Load from c.xls

else load from B.xls

End if

[martyn_birzys]

You may find this useful:

http://www.qlikviewaddict.com/2012/02/checking-file-exists.html