code open the external links in new tab, or new window

Hi all,
I have a problem to open an add in my app in new tab, it is opening in
the same tab of my site.

in my view I have added
<%= show_industry_sponsor(@community.industry) %>

and in application_helper.rb
def show_industry_sponsor(industry)

     return “<a href=‘http://www.someurl.com
onclick=‘window.open(this.href,’_blank’);return false;’ ><img
src=‘http://jobeehive.com/images/industry_sponsors/somurl.jpg
title=‘aaaaaa’ /></a>”

end

please help me out.. its urgent.