Crystal Reports Suppressing of sections based on two conditions

Message

   Hello

currently, I am trying to suppress a section of group based on two conditions:

The first condition is to suppress the section always if the user is not at DrillDownGroupLevel 1.
The second condition is to supress the section if the GroupName ({Customer.TerritoryID})  is not UK or US. 
I went to the section expert and entered this code in the "Suppress (No drill-down)" x-2 formula field:

DrillDownGroupLevel <> 1 AND 
(
GroupName ({Customer.TerritoryID}) <> "US" OR
GroupName ({Customer.TerritoryID}) <> "UK"
)

Unfortunately, it does not work. Any ideas are very welcome!!

I am using Crystal Reports XI

Thanks in advance!! 