Qlik Error on next expression.

[tenmaster10]

hi, i have the next expression:

count({1<MES={$(=num(Max(MES)-1, '00'))}>}ID_ITEM)

for take the total to the past month, but this don't move when i do something selecction.

i try to do the next

count({$<MES={$(=num(Max(MES)-1, '00'))}>}ID_ITEM)

or

count({<MES={$(=num(Max(MES)-1, '00'))}>}ID_ITEM)

but this give the result to 0.

i need help.

and sorry if my english is not very well but i'm learning.

thank you so much.

[Anil_Babu_Samineni]

How is the field rows MES looks like?