Seeking for a flat!!! (Bern)

Hello, everyone in Bern~**~
Greetings from Geneva!!!! :D

I recently got a short-term job in Bern, which starts from the mid-June.
Is it also almost a nightmare to find a flat in Bern?
If any one has experience, could you tell me which website I may refer to?
Or any flat or room to offer? :)
I am sure commuting everyday from Geneva to Bern is not a very clever idea :(
T-T
Help me!!!!!!! T-T