image in product does not load...

You have javascript errors on your page because of that problem:
www.hikashop.com/en/support/documentatio...ty-issues.html#modal
Please try the solution proposed there.

The modal.js file is a joomla file. Just download the joomla installation package and you will have the file in it.

Did you install a jquery plugin and configured it properly ?
There are several of them you can try. jQuery Easy sounds to be one of the best.

The plugin definitely helped clean the jquery mess in your headers.
There are still some javascript errors however.
Could you deactivate the mod_swfobject module and try again ? It seems to be causing some problems too.

I can still see the javascript errors coming for that module:
Uncaught ReferenceError: swfobject is not defined
(anonymous function)

and:
Unsafe JavaScript attempt to access frame with URL changeitback2012.com/store/product/1-cha...ack-2012-shirt-black from frame with URL temp.changeitback2012.com/modules/mod_swfobject/lib/dark.html . Domains, protocols and ports must match.

You can see them in your browser's javascript error console when you display the page. You could try to uninstall it. That should prevent the files from being used.
Also, if you still have other javascript errors after you remove these coming from this module, you might want to ask the support of the jquery easy plugin why you still have these errors as these plugin should remove them. Maybe you didn't configure it properly ?

To get back to the lightbox error, you will first have to fix the javascript errors on your website as they prevent the lightbox system of joomla to run properly on your page.