count null and non null values problem

[#1]

Hi im trying to count all "LanID" where they have 2 or less then 2 " DocName"  and the null values for those that dont have any "DocName"

=count(DISTINCT {<LanID = {"=count(distinct DocName)<=2"}>}LanID)

+  count(DISTINCT LanID) -count(DISTINCT {<DocName = {"*"}>}LanID) 

This is my expression

The problem is when im trying to implement a YTD , MTYD and LYTD to this, it gets tricky,

For example :

All LanIDs that have <=2 DocNames including 0 and null value is = 198 LanIDs

When i press the current Year = 136 LanIDs

When i press current Year and choose Oct and Sep = 146 ,

How  could this be ?

I have tried with NullCount and adding the LanIDs manually, but wont work..

Any Help would be much appriciated .

[sujeetsingh]

Post a sample plz