One possibility is that you have a pop-up stopper (Google's is an excellent one BTW) and because it wants to stop a pop-up a bit of JavaScript later in the page can't run. Everything is ok, just say you don't want to debug.
As you are not a techie (I think?!) you don't need this switched on anyway. So if you are using Microsoft Internet Explorer, do the following. Click on "Tools" on the menu bar, then select "Internet Options" and click on the rightmost "Advanced" tab. Look down the list of things to about number 6 and tick the box marked "Disable Script Debugging". Apply this change and hey-presto! No more annoying messages and your pop-up stopper will still be your friend.