Feeling nervousness before the interview is a normal thing. However, it is not very helpful. The article gives hints on how to learn not to feel butterflies in the stomach.
Handling Interview Jitters
Handling Interview Jitters

An interview is always stressful. People get wet hands, trembling knees, stomach aches and strange feelings in the whole body. It is normal to feel anxious before a job interview, for one of our greatest fears is rejection and one of our biggest needs is acceptance. However, panic attacks won’t help you pass an interview successfully.

jittersChange your way of thinking. The best way to fight your fear is to look at interview from perspective. You are not going to be hurt and the worst thing that can happen is that you won’t get the position, which may have appeared to be a wrong position for you, anyway.
Besides, think about the interview as a two-way conversation. Not only does the interview get to know you, you are also interviewing him/her to figure out whether or not this job suits you.

Use calming techniques. Learn to breathe correctly when you are under stress. Inhale through your nose and exhale through your mouth taking shallow breaths. Yoga and meditation may be an excellent preconditioning in helping you manage panic attacks before the interviews.

Prepare before the interview. Interview is the process of presenting yourself or even “selling” your skills and knowledge as well as yourself to the employer. Every presentation should be prepared and practiced beforehand. When you have spent some time to get ready, you will feel more confident and relaxed.

Get rid of fear of rejection. When you go through a number of interviews and get one rejection after another, your self-esteem may suffer as well as you may become afraid to get one more rejection. Take it easier. Don’t take it so personally. There may be tons of reasons why you are not accepted: there may be a person who was promised a job, or some friend of an influential relative, or you may also be overqualified for the job.

Let it go. After the interview is over, praise yourself. You have got quite far, not many people are invited to be interviewed. You have experienced stress and there is something to learn from each and every interview. Remember: if it the right job for you, the offer will certainly come through.