Thanks!
So with the fullscreen slider addon activated, this is how it works:
http://laythemeforum.com:4567/topic/947/scroll-to-anchors-with-fullscreen-slider-addon-back-to-top-button-doesn-t-work/2
If you don't use the fullscreen slider addon do it like this:
http://laythemeforum.com:4567/topic/696/links-to-content-on-same-page/3