[OpenLayers-Users] displaying specific polygons from one layer

[kuba]

I would like to know if it is possible to make a request to WMS server  
in such a way that  the polygons with specific  attributes. i have map  
of Europe and each country has  following  attributes   name, area,  
member of European Union. Basically i want to display only the  
countries of european union.  Is it possible to make such query using  
getMap

Kuba