Unless the site has "fully loaded" trying to click the check box next to a piece of SPAM e-mail to select it and mark as SPAM fails to do anything but to try and read that e-mail. On slower internet connections, this a very severe problem. Ideally in your mark-up you should have selecting the checkbox be selectable without triggering reading the message as currently happens when the page is not fully loaded. Triggering read instead of being able to mark as spam means that more spammers have your email address and the amount of spam you will receive is likely to increase. Please fix this issue ASAP.