the reason of shyness

Be confident. Tell yourself that you have great qualities, and don't let anybody bring you down!
Set goals for yourself. Focus on small, daily goals, and gradually become more daring. E.g. try to speak at least once every class period.
Introduce yourself to new people each day. Most people are nice and will be welcoming to your advances. It is also great practice for more daring behavior, such as talking to cute people.
Hold close bonds with your friends, they can be there for you when you crack out of the shell! They'll be glad to help.
Try doing stuff you never dreamed you would. For example: Talk to that cute boy in study hall that you thought would never notice you. Wear something very flattering and colorful to show what a fun person you really are!
Laugh often, at your own jokes and those of others. It will help ease any tension you may be feeling.
Lie on your bed and take 3 deep breaths. Then visualize a situation where you might be