problem with non-English language

[Musta]

Hi, I need to translate this great cart to Czech. All works properly except connection to MySQL server.
Czech has special diacritical letters (I'dont know if it will works, but here they are : ěščřžýáíéůú).
MySQL is set as win-cp1250 (for Czech), and in the code I have mysql_query("SET NAMES 'cp1250';");

Some things are displayed properly, but some things not.
Categories and all option of product like description aren't displayed well and it is displayed with ? for example ?e?ník.
-It is recorder to the database in correct form, but It is readed from the database in incorrect form.
Please, can you tell me where I have to place mysql_query("SET NAMES 'cp1250';"); or what I have to do
to make it cerrectly.

Thanks for each opinion.