If one website is opened with two different domain than what negative effects will be there?

[Dinesh]

If one website is OpenID like dis :- http://www.seconduserfurniture.co.uk , seconduserfurniture.co.uk , 2nduserfurniture.co.uk , and with all urls there is the same website.
Will there all urls have a negative effect on website in terms of SEO ?

[Sophia]

NO there will not be any side effects, if you are trying to target regionally,
But the thing that hurts is how you are using the urls. It seems that .co.uk is the main site you are using, it will be given more importance than others

[DreamDezigns]

When a site differs in the top-level-domains (TLD), then duplicate content was not an issue, a year back. But now it has some least draw back after Google’s Panda update. So if your site has different TLDs, use unique content tailored according to countries you target.

When the domain name is different, but it deals same thing about one of your other sites, then you should be very serious about not duplicating the content. And assign a different C class IP address for the new site.

[Vashu]

it does not mean anything.......
in
http://www.seconduserfurniture.com
and
seconduserfurniture.co.uk
in both url( uniformly resource locator) domain name is same that is "seconduserfurniture"

well..
.com is a general networking site... and
.in is India,
.uk is United Kingdom