...
JavaScript client validation is not available for visitor validations.
...
Because client side validation does not talk to the server, the theme (xhtml theme or css_xhtml theme) is responsible for properly manipulating the HTML DOM to display the error message inline. The JavaScript that is responsible for doing this logic is validation.js and can be found in each theme.
...
...
Errors are reported using the default validation message, not the internationalized version that the server-side might be aware of. This is a known issue. You may want to try the AJAX Client Side Validation for messages that are fully internationalized.
...
Additional Validator Support
...