Nina45 has the gist of it. There are a couple of things I can add to it.
BE SPECIFIC in everything you say. The interview is set up with the second person keeping a score sheet on your answer. The interview score sheet has guidelines.
You can be scored Red Yellow or Green.
To get green you not only have do decribe a specific situation, but you ALSO have to say what you did to resolve the issue.
For instance one of the questions is to describe a time when you gave good customer service. Describe a time you did, and give the specific steps you took to resolve the customer issue. Not just, Oh I helped this lady get something off the wall. Something along the lines of, a lady came in wanting money off her purchace because she left a coupon at home. I called my manager to see if it was okay to take the discount off. I gave her the discount with my managers approval and she left a happy customer.
Second, ALWAYS say that the employee should be fired imediately if caught stealing and should go to jail. Never say anything about a second chance.
Third, and most important, when you are asked if you had a confilct at work. Don't EVER say I have never had one. Keep it postive and decribe the specific situation and steps you took to make the situation better. DONT! talk about any conflict with a manager or time off. Talk about with a "co-worker" and how you guys worked it out.
Even better talk about a specific work related conflict such as finding out how to properly do a job after being told to do it wrong. Try to keep it non personal.