How to delay an email response if no user action?

[uberdragon]

Hello all first I'll detail the project at hand:

I'm writing landing pages for advertisement content in flash. The flash content will capture name and email information and then send the surfer to my landing pages to be encoded in PHP. I will capture the data sent via POST and that should consist of name and email at the very least.

The question presented to me is:

If the user abandons the landing page (doesn't fill in the additional info) is there a way to automatically email that surfer (based on the email information passed from the Flash ad).  They would like this email to be generated 24 hours after receiving the data from the initial advertisement only if the user didn't continue to the remaining pages.

I've been grappling with the concept and how I would handle this. Making things happen based on user input is easy. But this needs to react if NO user interaction happens.

I have considered simply placing the data sent from the advert in a database for storage, if the user completes the additional form on the landing pages it would complete the data row in the database. I could then check to see if all data was filled in and if the database row only holds name and email, generate an email to the recipient.

The only way I can think of to initiate the checking of data to see how far the surfer got is by the next person to access the landing page. (each time the landing page is viewed it runs a check of the database fields, if it finds only name and email, it fires of the hello email to surfer and then fills in another field in the row such as: Emailed to TRUE causing the next refresh to not email that data row again).

This ofcourse relies on the next refresh to initiate the check of db data and I would imagine could cause things to get very slow as that database fills up.  And it doesn't delay the email generation by 24 hours as requested.

Any suggestions ideas? I'm not looking for code neccesarily just a concept on how to make this happen in the most efficient manner. I look forward to your comments.

~Shane

[ignace]

php has a function that executes certain commands whenever the clients disconnect, don't know if this is it, but maybe worth checking: http://php.belnet.be/manual/nl/function.connection-aborted.php