You mean something like
this ? Clicl on the "
Technical Specifications and Features page." link in that page, to see how it pops up. If this is what you want, it is very simple. Let's say that you have created a small page (200 x 300 pixels) with the dates that you want to display in the popup.
In your original page, create the link. In the Link dialog box, in the URL field, type this code:
This is ok, if you have the page in the same folder. If not, replace "yourpage.html" with the full URL: http://yourdomain.com/yourpage.html"
300 and 200 are the popup dimensions, change it to whatever you need it to be.
Oh, it can also be a php page, not only html.