How to open links in SSRS report from Iframe

How to open links in SSRS report from Iframe

I am using iframes to house my SSRS reports.
I have a report that has links to external sites.
The expression is ="javascript:void(window.open('" + Fields!Url.Value +
"', '', 'width=1000, height=800, top=0, left=0, resizable=yes'))" which
opens the link in new page or tab (requirement).
When I try to open those links from Report Manager, they work fine.
But when I am clicking the links from within the iframe, they don't work.
So, I need the links to work and also they need to open in new page or tab.
This, however, doesn't happen in Google Chrome. Issue occurs only in IE
and Firefox.
Thanks in Advance.