Please Help I have no idea how to do this!

I have to prepare a adjusting entry for year ended December 31, 2008

A. One third of the work related to 15,000 cash received in advance is performed this period.

The company has a bank loan and has incurred but not recorded interest expense of 2,500 for the year ended December 31, 2008. The company must pay the interest on January 2, 2009