Direct Access

I have a web site in asp where I do not want the users to
directly type in the URL
of some pages in the browser. For e.g. the main page
is 'index.asp' and depending on
the users resolution either 'mypage1024.asp' or
page 'my800.asp' would open up in the
browser.
What I want is that no user should be able to directly
access the page by typing in
the URL www.mysite.com/page1024.asp or
www.mysite.com/800.asp. If a user
tries to access these pages directly then they should be
forcefully redirected to the
home page www.mysite.com/index.asp and this page would
check the resolution
and load the 'mypage1024.asp' or 'mypage800.asp' depending