C4SpeeD Hacked my webpage

This hacker "C4SpeeD" change the name of my blog, has access on database, an else more, but i thank god that he dont erase my site like this : http://www.switch05.net because i dont have any backup on my site, tonight ill have my first backup :P.

I didnt know to many hackers that want to be known, almost all hackers start and begin in anonymity. Here is the details of him: http://www.hotornot.de/profil.php?userid=656529&a=c

I just want to say thxs c4speed, and hope u can tell me my vulnerabilities on my webpage to make it more secure.