My project is coming along nicely! A brief background on my project. I have a world map that is colored to show the country of origin of the students at a college. Each color represents the number students (a range). E.g. any country colored red has 1 to 20 students at the college. When you click on a country, I was successful in displaying data specific to that country in a pop-up. 

Hopefully I can describe what I want to do next.... I want to add the ability to query the map such that the countries that satisfy the query will be highlighted on the map.  

So for example, in my html form I enter > 300... click on submit.... England, India and USA are highlighted. I've figured out that I need to use WFS getFeature but as you can see it's the how that I need help with... 

Can anyone direct me to an example of the above or give me some suggestions, I would be most appreciative. 

I am using MapSever, PostGIS and Openlayers 

Chris