Never, Under ANY circumstances tell your Interview Board that you need the job so you can pay off debt, NEVER! Not only does it show you can't manage a simple checkbook, But it also shows your not responsible to some degree. Do make note that some Employers, take mine for example, the LAPD, Do run credit checks/reports on applicants. I had to go through one, because Employers DO NOT want people who can't do something as simple as manage a checkbook.
Aside from all that, If your in for the 2nd interview, Good for you kid! Personally, with the 2nd and 3rd Interviews the job at that point is yours to lose.