Before everyone starts going out to buy 6 ft lengths of rope, maybe I can give a slightly more positive slant on Puritan's post. Everything he says is true, however in my experience all the guys and girls I kept in touch with who were on my course (around 4 years ago) have now got airline jobs (or jobs they are happy in). It took some of them up to 2 years, but in my experience provided you are a strong candidate then eventually you will succeed.
Provided you have a strong training record (I don't mean first time passes at everything, but at least in a reasonable time frame, and a good final report), and you have GOOD CRM / PEOPLE SKILLS, then you should succeed eventually.