I have a form generator that uses (perl compatible) regexes for ther backend validation. Since the whole form is being dynamically generated it was fairly trivial to add a
PHP preg_* functions and JavaScript both use Perl-compatible regular expressions. In principle, they should support the same set of regular expressions.
You really should give some examples of what is not working, because it is very likely that your problem is due to escaping/string handling.
Read about specific implementation details for Regular Expressions in Javascript.
JavaScript implements Perl-style regular expressions. However, it lacks quite a number of advanced features available in Perl and other modern regular expression flavors
For one thing, the / character denotes the beginning and end of a regex in Javascript, so you might need to escape it, but that depends on how you're instantiating the regular expression in Javascript (with the literal notation or the RegExp class).