WordPress Problem

Hey guys, can somebody help me with the following, so I made this website for a school project. And it is finished, but the problem is, that javascript and jquery are not working? Why is this, maybe it is something i overlooked??
this is the website:
http://lefke123.com/private/dvdb/
example what is not working:
the slideshow plugin, also the calendar widget in the sidebar :/
Any help is welcome!
Answer #1
okayyy after long searching i got it..
Maybe it can be useful for others who got stuck in the same stupid situation :p
at this to your header
<?php wp_head();?>