How to not get nervous?

I used to have the nervous problem as well... everytime I go on stage I get butterflies in my stomach but at the end I found out that i was thinking too much.. what you have to do is just calm down and relax and don't worry too much... or keep reminding yourself that you can do it.. after a while of this , you'd gain confidence and everytime you have to face these situations you'd be as flexible as ever (: