I found the solution, in my Templatefile the "/media/system/js/core.js" was unset. Now the reservation works fine with Joomla 3 and Book it! 2.0.7.

Hello Maju

I reinstalled Joomla 3.0 and setup all new, with Book it! 2.0.4. Unfortunately I get the same Error on the submitbutton, when I try to make a reservation.

Thanks for help, Nic!

When I make a reservation and push the submitbutton, the following error happens.

ReferenceError: submitform is not defined
submitform(pressbutton);

I'm using Version 2.0.1 and Joomla 3.1.1
Any help would be great, thanks!