onexit stay 1min on page script required

Hello everybody! i have script already designed in PHP&JS. Example: [login to view URL] you will see banners on page. while loading page click on exit then you will see alert popup click ok then it will stay user on page for minimum 1min but banners become loading during this time. after one min it will show again new alert click here ok again ok and page will be close. Note: This script will be work on all latest browsers like IE9, Mozilla, Firefox. but it is not working on old browsers+IPhones like IE-6, IE-7, IE-8 etc. i need to run same function on all browsers+all OS like Mac, Computer, Mobile. For more detail you can touch me on skype:cpmadserver Regards, CPM Adserver Pvt Ltd: