you could of course type the two terms in google and find this link as the first result: http://www.codeguru.com/columns/experts/article.php/c4651 i think it quite nicely answers your current questions..
maybe next time try google first, and if that doesnt answer your questions than post a question of more than 1 line stating what you have found and what is not clear, maybe than a more usefull response can be given.
answered 1 year ago
by anonymous