session / cookie

[Rex_chaos]

Hello all,
I am new to PHP. I have a index.php for login. After having login, the user's information will be shown on the right hand side of the page. If then someone press the BACK and FORWARD to reload the index.php, the user's information still there. How can I have the user relogin when they REEnter the page? Someone told me session/cookie is suitable for this case, I have no idea. Anyone help? Thanks.

[sfhc]

I have no idea why you would want to so inconvenience the user, but anway.

Either sessions or cookies would work.

Session may be better because users can always delete cookies.

session_start();
session_register('forceLogIn');

if($_SESSION[forceLogIn]=="" || $_SESSION[forceLogIn]==0){
     // session var is blank or equal to zero
     // build log in form, don't display user info
}

The way that works, if the var has not value, it is likely the first time they are at the page, so naturaly they have to log in.

On sucessful log in, $forceLogIn is set to zero.

Hope that helps.