What creates phlegm?

*This post maybe a bit disgusting, but good for your knowledge*

I've been coughing really badly as if my lungs are throwing out any minute.  As I was coughing in the car this morning, Tengku Mahkota said 'Throw OUT!' My response was 'You think so EASY?' Do you know how much of strength is required to throw out? My head turns dizzy and followed by chest pain everytime i cough. 

Next question came...'What creates phlegm?' After reaching office, I started to goole and I found a good link that provides good explanations to this:-

http://poznaisebya.com/newsengall/home-health-care/news_2008-06-09-11-17-03-123.html