Problem in log out?

Question

hi!
i am using this line (code is write under form load)
Page.RegisterClientScriptBlock("", "<script> if(history.length>0)history.go(+1);</script>");
using this when i click logout button in my form i am goto log in page and  click back arrow button of web browser it display login page. its working and its fine. my aim is also when i logout then goto login page.
 
but my problem is i worked another pages of project  if i click back arrow button of web browser. it is not go to back page it still on that page only. it is inconvenience for me.
 
my aim is when i click back arrow button of web browser it goes to back page but if i click logout button when i click back arrow button of web browser, it display only Login page.
please give a code of this doing.
Thanks