who's been logging in and on which computers ?

Hi,

I need a (powershell) script to tell me who's been logging in to the domain (server 2008 R2 standard) and on which computers.

And if possible times

E.g. output might be somthing like this in excel

User    Computer   Login            Logout

fred     PC1            wed 8.00      wed 17.00

fred     PC2            wed 9.05      wed 10.15

bob     PC3            wed 12.15    wed  19.20

I'd like to be able to get data from the past e.g. the "last 6 months"

any pointers to get me started ?

Thanks

Ed