Is it possible for GNU to automatically add interest? also automatic payments?

[Mark Davis]

So I am trying to set up my Student loan, also this would be nice for
credit cards. But I am trying to put in my school loan that is
interest rate of 6.8% is there somewhere in the program I can cause it
to automatically calculate the interest at the end of the month? Here
is a screen shot of my latest student loan bill (of course all
personal information removed minus the amount of the loans. and I also
have a screenshot of How I currently have GNU cash set up any help is
appreciated!

GNU Cash
http://img.photobucket.com/albums/v66/Callsignbishop/GNUCash.jpg

Student Loan
http://img.photobucket.com/albums/v66/Callsignbishop/StudentLoanBill.jpg

Thanks