view message marked as read

[tr8er8]

i have a page that shows a pm that a user sent to the certain user. and im trying to make it so that when the user views the page for at least 5 seconds, it updates the database to `messageread` = 1, in this case 1 means it has been read, 0 means its unread. but im not sure how to approach the viewing for 5 seconds thing, so i came here to ask if anyone has any suggestions?

[cameraman]

I can't think of any way to do it without javascript: onload set a 5 second timer, then send an ajax request to a script that would set the flag.