tests for students

Hello
I'm going to be a teacher in one of the language schools, and I'm supposed to give my new students an entry test to check their level of English. Which one would you recomend?
What is it better to include there?
Thank you.

[Tdol]

It really depends on the levels you have in your school. There are standard tests like the Oxford Placement tests,which run through grammatical structures of increasing complexity. There are also online assessments.

Will it just be written or will you interview them as well?