I want a popup window when opening site for first time

Hello, I have been using ZenCart for long time and it is such a great CMS for managing shops. I have finally come up to a problem which I don't know how to solve.

I need a popup window (like lightbox) which will popup when zencart shop loads, only the first time user opens it.

This is the thing I need: http://www.indras-planet.at/shop/index.php

The popup window will open only on the first visit, and every other visit of the same user it will not open.

How is it possible to do this, is there some addon/plugin for this so I can edit the content later from administration?

I am using v1.3.9.

Very important for me, please anyone help.

Thank you

Anyone knows?
Using javascript?

Hi Marko,

Take a look at http://coverpopjs.com. Not used it myself but it is cookie based and should be easy enough to add to your template :)

Thank you jonnyboy for your help, I will test it soon and reply here with results.

Thank you very much jonnyboy22, this the the job after I have been looking long time. Thanks!

You're welcome :)