Topic: Aligning the top of main image with thumbs

Hello everyone,
i put together a website a couple years back and i decided it was time to update my gallery's and add some new one's
However, i cant get the top of the main image to align with the top of the thumbs anymore.
It's probably been to long and i forgot.
This is what is should look like:
www jdeboomfotografie nl/vrij/vrij_werk html (sorry, but it seems i can't place the dots in the link)
any help would be most welcome.

Greetz Jesse.