Help with buttons?

Hi all,

This might incorporate some javascript too, but I'm not really sure so I'm going to ask it here anyway as I'd rather do the whole job with php if possible.

I'm trying to make an HTML converting assistant for someone on our staff - something where she could just press one of a few buttons above a comment box on a page and insert a br tag or font tag etc into the comment box where the cursor is.

How can I do this? I have a sneaking suspicion it's more js than php... either way, I can't figure it out.

Thanks in advance!