Learn some Javascript. JS is, imho, a better language than Perl for many reasons. It's still a bit immature, but has features I wish I could have in Perl.

IMNSHO Perl and JS are just different and hardly one of them can be "better" than the other as a whole. I'm a great Perl fan and for a long time I've had an attitude wrt JS, then I looked into it and was pleased to discover it's a neat little language with interesting features, so that all in all notwithstanding the fact that AS's PerlScript shows how Perl could be used for client-side scripting, I think that JS is much better suited for that task. Indeed I find that the whole idea of a structured markup language with an associated DOM and a scripting language to operate on it (and perhaps on browswer's elements - but then there should be some more standardization on browser UIs) is wonderful. In this respect, the language I love, i.e. Perl is probably too wild in many ways, and JS could be closer to the ideal one for this area of application. What bothers me is given by the too many dialects and differences across implementations, but behind the current mess I can see an ideal markup and an ideal scripting language. One then has plainly to live with the real-world approximations to it, and cope with their imperfections. OTOH I would hardly use JS as a general purpose programming language.