I've tried a lot of times to use the OpenLayers CQL example but nothing changes. Is there any way to use CQL or filter.
You have CQL in example:
Try to change B to A and you will see change
BTW OpenLayers supports less function then GeoServer but you can read http://docs.geoserver.org/stable/en/user/tutorials/cql/cql_tutorial.html
try to use this code:
dont forget VERSION is important for getting true result.
i hope it helps you...