Best way to make a php/mysql notification system, (like facebook)

[shortysbest]

Im building a social networking site and i want to have a comment notification that alerts the user when they have a new comment. I'm wondering how i should go about doing this, such as how my database should look.

[freelance84]

Alert how, by email?

 

one way would be

A user types message to another user, when they click post it posts the message but also sends an email out to the recipient too using mail();

[shortysbest]

the notification on the site itself, like on facebook at the top bar.

[freelance84]

In the members table have a "new message" field. This could be a 1 or a 0. If 1 then there is a new message.

 

When the script runs it get the "new message" content and displays your notification or not