[Plugin: WP-BANNERIZE] Random Banner

Hi there, can someone help me out? I am not have any luck with getting the plug in to run a different banner on each page load.

My website is https://www.theccea.org. The logo in the side page should either be a place called the Signature room or a Photographers ads but the following code does not seem to work.

So what am I doing wrong?

<?php wp_bannerize(‘group=a&limit=1&random=’); ?>

Thanks,
Darrin