Hi,
Hope your query is about the page redirection using an external javascript file.
For this reason, the following code can be placed in a separate file and then called in your page's head section.
It causes redirection in a new page.
hope this code does satisfy your intended purpose.
Code:
var wnd = window.open("http://www.google.com","_blank","true");
you may find more details on this arguments on my blog at :
http://dsaravanan.wordpress.com/
Regards,
d_s