Right! After some amount of trial and error, I realised my mistake... it wasn't the fault of the Javascript at all.

One of the first things that I did when I installed vBulletin was to go through and add the width and height attributes to all the image tags. All smilies were set to 15 pixels x 15 pixels by hardcoding it into the relevant template. Now, in order to add larger smilies, I made use of the replacement variables section. This allowed me to add the smilies - with the width and height attributes.

This worked fine - until now. Obviously, when the system does the replacements, it is now replacing the :dunce: in the Javascript with the replacement text specified elsewhere.

So, as I saiid above, it looks like i'm stuck without these larger smilies That is, unless John sees fit to modify the smilies table in the database in the next release so that it includes width and height attributes...

Sorry for wasting your time, Mr B, and thanks for the help...