Snag fixes on WordPress based e-commerce system (ShopperPress)

We have two small snags to fix on our customised ShopperPress system:

1 - At the final stage of our checkout process, the options to "Pay by PayPal" and "Pay by Post Finance" do not currently work. When you press the buttons, nothing happens. It is probably a JavaScript or PHP error.

2 - At the start of the checkout process, there is additonal text displayed that should not be there, e.g. "language_english". It is produced by PHP. See attachment Gallo1.jpg

We have regular work for a good PHP developer, so a successful completion of these tasks will probably lead to further work.

The website is on our development server: http://79.170.44.135/vdegallo.ch/