If any one of you created the Force.com default Recruiting app. I have a simple yet weird question for you guys. I can't see any Job_Application object in the related to list.

Let's start by adding the master-detail relationship field, which will relate our Review object with the Job Application object. To create the master-detail relationship field, access the Review object detail page.

4. Select Master-Detail Relationship, and click Next.
5. In the Related To drop-down list, choose Job Application, and click Next.

So I'm stuck at 5th point. I have Job Application object created already, which have two relationships in it, one with Position object and the other one is with Candidate object. Pleas help.