I'd agree. When I started at my current job (my first real programming job, other than what I did when trying to learn), I knew very little of HTML, JavaScript, or any other language, really. In the year and a half since I've been here, I've learned quite a bit, becoming (in my humble opinion ;) ) one of our best coders, and if you're dedicated to learning and succeeding, you really can't go wrong. Like the poster above me, just go for it and try.
Upvote. At least in Australia, it's pretty hard to actually get fired (generalisation, but holds up pretty well). There's no harm in jumping into something, taking a hit with the learning curve and busting ass to get up to speed. If a year down the track you're embedded into the process / team and performing, nobody will give a shit that you spent the first three or five months building up your skill / role.
It's a better model then getting into something you know you're fully capable of and having no incentive to perform like hell. Comfortable but mind destroying.
>What's the worst that can happen?
Ending up on a pip which ruins your career.
When I started as a junior html developer I'd written exactly one website, a really poor 1997-era personal homepage. I didn't even know what a html table was, I'd never done forms, etc etc. It was a really junior role, but I figured I could learn what I didn't know on the spot. I stayed at that company for 4 years, and left with the job title "Senior Database Programmer". I'm now a highly experienced developer with some good academic qualifications too; I joined my first university on the strength of my experience alone, which was that first job.
Stop worrying and go for it. There's a crapload of documentation online, so even if you really are a bad developer you should be able to squeeze by until you become good enough.