Dandruff..!!

It is not a good thing to have it on our head's skin. I do have this dandruff problem since I was in form 4 until now. It makes my hair oily, itch and felt not comfortable for the whole day. I still remember went I was taking biology subject in secondary school my biology's teacher say that it was a common condition. This is because dandruff is formed went the old skin of the head was renewed and the old skin was pushed onto the surface of the head and that is how the dandruff get in your hair. A friend of mine said that dandruff can be produced frequently in the hot temperature which means the renews of the skin is faster. That's the only facts that I know about the existence of the dandruff in my hair. I've tried so many product of shampoo but none of those product can solve my dandruff problem. The dandruff makes me feel shy went my friends saw or talking about my dandruff. It also makes me unconfidence with my self and lose focus to the lecture.How I wish I can say "Bye bye evil dandruff and do not ever come to me again"...hahah... if there is anyone that can tell me on how to treat this dandruff problem please tell me if the dandruff cannot be vanished from my hair at least it can reduce the amount of the dandruff.