white screen on macbook pro 2010

Basically I put in the first installation disk and it asked me to restart which I agreed to. It turned itself off and then came on. It then went to a white screen and froze there. I have tried pressing all the keys and the only one that works is pressing the power key which eventually turns it off. When you turn it on again it just turns on to the white screen again and stays there. The eject button doesn't work so I can't get the disc out. I have tried let the basttery deplete and then turn it on again but still get the white screen. Has anyone got any ideas please?

To get the disc out, try holding down the mouse button during boot. If that doesn't solve the problem (the problem isn't the disc), reset the PRAM (instructions here). More info about the PRAM here.

Great thank you. Holding the mouse button worked immediately .