SQL query problem with any language except English

Hello guys,
i've the following table in database :

IdCity int
CityName nvarchar(20)

it has the data like this in it :

IdCity CityName
1
2
3
4
5
6
when i try to run the following view

    SELECT       IdCity, CityName
    FROM            dbo.City
    WHERE        (CityName = '')

i get the results null, althought that record in the table
i tried to add a record with cityname= 'abc' and ran the view with this parameter, it worked fine
so it only doesn't get results written in russian
any ideas?

SQL query problem with any language except English