HALP!

[cazzasaurus]

Can anybody help? On my other laptop, when I made a typo in Livejournal (a post or a comment) it would underline it with a squiggly red line, like in Word. It doesn't seem to be doing it with this one and I can't remember how I made it do it, or whether it was an add-on I downloaded. Anyone else have this feature? If so, where's it from please?

Thanks!