template crashes in shopping cart

Dear Sirs,

The same problem occurs now on www.opleiding-medische-basiskennis.nl
when changing amount in shopping cart or choosing different payment method
the template crashes ( the site jumps out of the template)

Can the above fix also be applied to this template? Where would I have to put it?

Kind Regards.
Darko Ivancevic

Ideally for that template you could place it in cart layout page or in head section of index.php of template, but you can also just put it in:

templates/hot_explorer/js/responsive_menu.js

although it is strange place for that code.