IPN vs Express, and PayPal with FRAMES

Two questions from this newbie - all help appreciated.

**Simple question: ** What are basic differences between IPN and PayPal Express - any guidance when I should choose one over the other?

More Difficult Question: Is there a problem with PayPal IPN and the use of FRAMES? I have my shopping cart in a frame so it is "wrapped around" with the same look and feel of my primary site. When I "check out" PayPal offers a "try again" screen. If I open the shopping cart full screen and "check out," PayPal is passed my order information and seems ready to go on.

I suspect this is PayPal security so another site doesnt hijack it in any way. Any way to keep the cart in a frame up until when "CONFIRM CHECKOUT" is clicked that it opens PayPal in a new window (target=_blank)?

Thanks!
Ned

OBTW, to see the site with and without frames:

https://www.megansbeading.com/shopping.htm (with frames)

https://www.megansbeading.com/catalog (without frames)

paypal dosnt work in a frame,

rather than putting zen in a frame, why not just incorporate yourt design INTO zen cart so that its seamless

Merlin, thanks for your reply. As to why I'd put ZEN in a frame, my main site has some other attributes that I don't know how to incorporate into ZEN. I want more artistic and creative control over the front pages of my site, FAQs, etc., so wrapping the ZEN CART with the borders and menus of my main site seemed a reasonable way to approach it. (And so far, it looks OK except this stated difficulty).

Since you are "leaving" your site to go to PayPal, the ideal situation for me would be to keep the shopping cart in a frame up until the time you click "confirm" and then to open the PayPal page in full screen (or at least separate window).

I can't find an admin option or the appropriate page to edit, to change the link behavior of the "confirm" button.

I appreciate your helpful response.

this is not an option,
you will lose the session,

however you can take your header and place it in the tpl_header.php
you can do whatever you want, the only limit to zen cart is imagination,
take a look at https://www.moissaniteco.com

That's a simple idea that had escaped me. The left border you see on the front pages of my site would be lost

https://www.megansbeading.com

However, that's not a big deal.

Again, thanks for taking the time to help out a newbie.

Kind regards!