Back screen after File Upload

[vijay]

hi

I have 4 pages in my website and iam uploading a file using rad controls in 2nd page and im redirected to 3rd page....if i want to go back to 2nd page again using "back screen" then iam getting "Webpage expired" message... and if i refresh the 2nd page  again, then im getting the values... What could be the reason?

any idea?????

thanks in advance

vijay