How Do I Reply?

I have a question. Does anyone know how I can reply to comments that are left on my blog? I've Googled it, and as far as I know I've followed the steps that should make replying possible, but to no avail.
Under each comment that you leave there are two options 'reply' and 'delete'; I click on 'reply' (unless you are spam, in which case I click 'delete') and   


nothing.


No box, no new page, no options whatsoever for leaving a reply to your kind comment(s). The only thing I've noticed is that when I hover over the 'reply' button down at the very bottom left of the screen the word 'javascript' appears. I Googled 'javascript' and discovered that it's something that can be disabled or enabled (and plenty of other gobbledegook that I didn't understand), so I had a go at disabling it to see if that would make any difference, but alas no.

So I've taken to either replying as a comment or else replying via your own blog, which isn't ideal, but at least shows I'm reading what you're saying.

Does anyone have any hints or tips they can offer? I'd really like to be able to reply to comments to show people that I do appreciate that they take the time to read/comment on my blog.