Thank you all for your help. It's been very useful. I will of course be talking to them about Perl as well.
For the record, as I didn't make myself entirely clear before, I will be showing them lots of cute JavaScript tricks in subsequent classes, but I'm setting the first six-hour lesson aside to talk about the basics.
That way when the tricks are being taught, I can at least say something like "and see here, that's the assignment operator, remember? So we're assigning a location to the window object, in other words telling the browser where to go" and have them feel less like they're just reproducing code and more like they're understanding it.
--
($_='jjjuuusssttt annootthheer
pppeeerrrlll haaaccckkeer')=~y/a-z//s;print;
