website popup for "monthly special"

Idea: have a jquery popup show to every 5th visitor on the site.

It would essentially be a 300px X 300px div, with a small form.

name, email, phone, comments.

each field will be required to process.

once they submit, i want to post back a .jpg coupon for them to print out.

pretty simple.

some questions i have.

is there a way utilizing jquery to only show this div to every 5th visitor?

is there a way to keep users from just typing the URL of the image and just print开发者_如何学运维 out the coupon without filling out the form? (would i just use a relative path?)

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This isn't possible with just jQuery, you would need some server side handling to

1. Count users (so you get every 5th view / user)
2. Generate a unique 'authorized' coupon (server side image handling with a unique url that expires changes).

jQuery would then be used for the popup, but ultimately the HTML side would be updated from the server side.