Hello Dave & In Omnibus...thanks for the great replies.
Yes I definitely hear you regarding the ad code from ad partners already including size/dimension code within the ad code they supply. I have worked (or am currently working with) at least 5-7 different ad partners...and all of them have included size info in the code they supply.
This includes Adsense, Media.net, Amazon Associates...and others.
I've mentioned this to this specific ad supplier...and up to this point they really haven't offered a solution where the "ad dimension code" is included within the ad code they supply.
What they seem to want me to do is...modify the vBulletin templates so their ads run in a size that's works for my website (modify the ad container size in the vBulletin templates). I really would rather not do this...since this will fix this ad location to just one size ad...and I'm pretty sure (from experience)...that the vBulletin ad locations/containers are responsive (many ad sizes will work).
Also...if I then decide in the future...to work with a different ad partner...or move this specific ad to a different location on the website...then the template that was modified will need to be modified back to it's original unaltered vBulletin code.
This can be done of course...but a lot of unnecessary modifying...since the ad supplier should supply ad code that works without needing to modify templates.
If anyone has any other ideas on how to modify the ad code so it doesn't run full size (full size in the browser window)...that would be awesome!
Thanks again for the help.