You've spent years working your way up the company, waiting for your chance to be promoted. You volunteered for the assignments nobody else wanted, developed your skills and thought you did great in the interview, but there's just one problem -- you weren't promoted. It's hard enough to deal with rejection when you're applying for a job at a company you don't work for, but when you have to see the successful candidate every day -- or worse, report to that person -- it's even more difficult to cope with.

Remain professional and support the successful candidate. Your boss is probably worried about your reaction, but this is a chance to demonstrate that you can be a team player. Failure to support the promoted employee looks like sour grapes and can damage your professional reputation.

Calm down and collect your thoughts before confronting your manager about the decision. John Beeson -- founder of Beeson Consulting -- suggests in a "New York Times" interview that employees tell the boss "I am disappointed. I am not challenging the decision, but I would like to come back to you in a few days and get some feedback that would help me manage my career."

Ask your boss, the hiring manager or a trusted mentor for constructive feedback about your job performance and what steps you can take to help you advance in the future. Avoid being defensive, critical or argumentative and don't interrupt. Approach the issue by seeking personal improvement rather than challenging the decision. As hard as it may be to hear the criticism -- and even though you may not agree with it -- you need to understand the reasons why you were not promoted.

Create a plan to build on any identified areas of weakness so you can be prepared when the next opportunity arises. Ask your boss to help by giving you the opportunity to gain experience in other relevant areas within the organization. Consider taking classes outside the organization or volunteering in the community if you can't gain the skills you need at work.

Evaluate your feelings. Determine if you are jealous, feel misled by your superiors -- for example, if you were promised the promotion -- or if you are angry because you feel you deserved the promotion more than the person who ultimately got the job. Knowing why you feel the way you do will help you strategize how to cope, for example by speaking with the person who promised you the job. Seek counseling if your feelings are extreme or you can't find a way to get past the emotion.

Look elsewhere. Sometimes you realize that no matter what you do, the company isn't going to promote you. Maybe the organization doesn't value internal skills, or you can't count on an internal recommendation from your boss. When the situation doesn't seem salvageable, you may be left with no choice but to look outside the company if you want to move up.