Webuser Forums: Java Script

Hi,
This is my first visit to this forum; I am desperate for some advice and you may be the folks that might be able to help...

My wife and I have built a site (with a little help) and have it online live. It is an e-commerce site (and I'd rather be upfront about that; we're not here to advertise it or sell you anything). We have spent months building it (literally) adjusting 'this and that' to enable it to be viewed in both IE and Firefox virtually the same. We thought we were doing pretty well until this weekend...
Now whenever anyone visits the site in IE as the home page loads a windows message pops up saying:

Microsoft Internet Explorer
Java Script Error
Description: Syntax error
Source:http://www.crystalharmony.co.uk/index.php
line 2
See more details?
Yes - Cancel

This error box appears on nearly every page of the site bar a few.

Yet when anyone views the site from Firefox; it loads perfectly ok without any such errors. We don't remember doing anything that might have altered any code in the last fortnight and we believe this has just happened this last week... Even when we look at the code for line 2 - there appears to be nothing wrong with it...?

We know nothing about Java.

I've searched everywhere I can to try to see similar errors reported and how people may have fixed them - but then end up even more confused...

We initially thought it was as a result of changing the menu; but have tested it (localhost) without a menu and it still raises the same error box...

If we click 'OK' or 'Cancel' - it then just loads the page as normal and all is ok - unless you navigate to another page when the same error appears...

If anyone can offer advice about this matter we'd be eternally grateful!!

Cheers

Element77