vLastYear and vThisYear question

[#1]

Hi,

I'm wondering if vLastYear and vThisYear is a universal thing in Qlikview or if it has to be set up in my Master calendar somehow?

Cause as it is right now I don't seem to get it to work. I'm trying some stuff out and found this expression I'm experimenting with but can't get it to work:

if(sum({$<Year = {$(vLastYear)}, Month = {"<=$(vThisMonth)"}>} LineSalesAmount) > sum({$<Year = {$(vThisYear)}, Month = {"<=$(vThisMonth)"}>} LineSalesAmount),

0,

sum({$<Year = {$(vThisYear)}, Month = {"<=$(vThisMonth)"}>} LineSalesAmount) - sum({$<Year = {$(vLastYear)}, Month = {"<=$(vThisMonth)"}>} LineSalesAmount)

)

[sunny_talwar]

It is not a universal thing and these variables need to be created either in the script or using the variable overview