Why won't my Sony SLT-A37Y lens not focus?

Hi,
I have two lens for my camera and one will focus on photos but the other will not. I push down the pre-focus button and nothing happens and then when i take the photo it is really blurry.

The camera itself is fine because when i use the other lens it works fine.
Just wondering why my sense is doing this and how i can fix it.

Any help is greatly appreciated,
Thanks.