when session was time out login page is displayed in the target frame
with this above line, I assume you have a page in which frames are used (for example - 2 frames). Now in one of the frames, you session is geting time out.
Now your requirement is when session is timed out then login page should replace whole page (which have 2 framaes)
Oracle certified Java 8 Programmer I (1Z0-808), Oracle Java Web Service Developer (1z0-897), Oracle certified Java 7 Programmer, SCJA 1.0, SCJP 5.0, SCWCD 5.0, Oracle SQL Fundamentals I, CIW Certified Ecommerce specialist