Url comments

Hi! Earlier I wrote to you because I wanted to know if there was a way for my guests to add their url to their comment. You said it wasn´t possible at the moment, but that I might consider a plugin. Well, I tried to install a few different plugins, but although I activate them, it is still the old comment-version that is showing. Do I have to disable it in some way for the other plugins to work? My url: www.greenattraction.net