For anyone else who struggles with absurd French website design here's Frederick the Frog's guide to French internet checkouts:
1/ Click the link above
2/ Scroll down a bit, click the Ajouter button (seems similar to add to cart)
3/ In the pop up thing click Votre panier (look at your French cart - the link is also up there top right)
4/ Look for Commander and click that. Probably means buy.
5/ You're into the French payment system. That's the easy bit.
6/ It asks for a intentifant (username) and Mot de pass (password). If you haven't bought from 4L international before you need to click the little button beside Nouveaux client.
7/ Fill in the form. Prenom is first name, nom is surname, ville is town, pays is country. You need to click the accept whatever their conditions are at the bottom.
8/ Press the S'inscrire button to submit the form
9/ They send you an email
10/ Click on the link in the email to confirm you are who you said you were in the first place.
11/ From the link find where you were before, or follow the link at the top of the page and go through everything again.
12/ Go through the process again until you find the bit listed in 6/ above
13/ it's easy from there - you get to pay via paypal.
14/ Steps 14 to 30 - Go through much the same thing with Paypal fair enough if you don't already have an account. At least it's in English this time
31/ Tickets - wOOt!!!!! You have to pick them up at the door - print out everything just in case.
Madness the whole thing - steps 6 to 12 might be unfamiliar - they are going out of fashion in other countries so are even confusing in other languages, but I've got a ticket!