Show the jQuery dialog after X seconds of page scroll

Show the jQuery dialog after X seconds of page scroll

Using jQuery 1.7.1, I want to show a dialog box to the user for both these
circumstances...
Approximately after 15 seconds when the page has finished loading if no
user interaction has been done i.e. page scroll, link click. The dialog
box should appear.
If after say 10 seconds an interaction (page scroll / form field click) no
further action has been done and the user is still on the same page. The
dialog box should appear.



The purpose of this is to show a 'do you need any help / feedback' dialog
to a user if they are still on the same page for a number of seconds and
haven't scrolled or have scrolled and not interacted on the page i.e.
clicked a link / form field.
In the dialog i will show a 'No help needed' link which needs to hide the
dialog and stop it opening again during the session. So if this link is
clicked the dialog and counter must be stopped for the remainder of that
php session.