Online Test for all GP BI

http://www.democpt.cambridgetest.org/cptApp/demoTest.html?method=languageSelection

password : ask your  Head of panel or Senior Assistant ( PK1)

For more info, read more info

PS. There are actually a lot more websites to test our proficiency....
1. http://examenglish.com/
2. grammar
3. English Test - Sentence Building

You can also search for the websites on your own..
Good luck!!!