NEED A new charger for my late 2007 macbook

I have a 2007 Macbook pro (model no. A1226) and for the past 4 years I have been charging it using the 85w charger that it came with. However this has now broken and I need to buy a new charger. I do not understand the new chargers they have in the Apple store online and I read some comments about them not being compatable with older macs. I was wondering which charger I need to buy that will work with my older mac. can i have a link for a compatible charger?

Any help appreciated, thanks.