(JavaScript) MD5 & HMAC MD5 implementation

Hi guys.

I looked onto the internet to find a javascript implementation of keyed MD5 (HMAC applied to MD5 algorithm). Since I couldn't find one - did I searched right? if there's one, I would like to know - I made my own. But as I don't know javascript PERFECTLY, I still wonder if some of you could give me advices about javascript compatibility (accros browsers) and ideas/suggestions on how to optimize it, mostly about 32-bit operations. I must confess that it hasn't been *fully* tested yet, but I'm pretty sure it's working good.

Another thing: I had to go back to the original implementation of MD5 (as described in it's RFC sheet) to be sure to implement HMAC MD5 right. So it's quite close to it's C counterpart.

Anyway, if some of you cares the source should be included with this post (zipped); so just take a look at it and give me feedbacks.

Thanks in advance.