A client of mine asked me if I could create a hotel reservation form with client-side validation and multilingual support and this is the result. It comes along with support for 4 languages - English ("en-US"), Bulgarian ("bg"), German ("de") and French ("fr"). The form labels and validation warning messages are stored in .xml files and parsed onload. The default language could be easily set by changing a single variable in the <head>...</head> of the webpage.
The localization files are easily editable and are stored in the ReservationForm/Localization/ folder. The form layout is pure CSS and may be customized by editing the ReservationForm/ReservationForm.css file.