how to create a remeber me tickbox on sign in of user

[eluser]dhananjay[/eluser]
if i will use this so if a user has remembered and i have set cookie
if anyone using same browser to access website he will be automatically logged in by using the previous cookie saved

i thin this will work in the way as is working if a user has remembered on login any one using that browser will be logged in there is no way that it will know that now this is a different user...