Use Javascript:
// CRTL-SHIFT-B
function boldThis(from) {
strSelection = document.selection.createRange().text
if (strSelection == "") {
document.commentform.comments.focus()
if (from == 2) document.commentform.comments.select()
strSelection = document.selection.createRange().text
document.selection.createRange().text = strSelection + "<b></b>"
}
else document.selection.createRange().text = "<b>" + strSelection + "</b>"
return;
}
set up some custom styles, etc. and create "button"-links like this:
<a href="javascript:boldThis();" target="_self" title="CTRL-@!#$-B">Bold</a>
In the above example, you have to name your form "commentform".