Catch Invalid Document.domain Set ?

I do my development on a local PC before putting the code onto a website.

Something I need to do is set the document.domain to the top level domain for a page. The top level domain will be supplied via config item.

The small issue is that my top level domain when developing is "mypc" and attempting to set document.domain to "mypc" kills the javascript.

I tried this as a work around:

Code:

But this still triggers a complete failure of javascript on the page. I also tried using eval to do it, but it still kills things.

It there another trick to try setting the domain without dieing that doesn't involve validating the domain string before attempting to set it?

[Edit] I am aware that it's dieing because "mypc" is clearly not a FQDN as it expects.