plz need emegency help with cookies

Question

hi every body

here is my propelm

i have cookies that contain the email and password

i want the cookie appears in all of the masters bcz  when insert values in database will be according to email and password

when i load the page i can get the cookie via

lbl.Text=Request.cookies["email"].value;

the project about  3 masterpages and 3 aspx pages

page to register its work fine

page to login its works fine

page to add information of subject its working fine but how can i insert data acoording to the user id or email????

so

 

when i click on hyperlink that back me to last page cookies are cleared

how can i deal with that???

 

if there are any way to insert data according to userid with out cookie