Add to favourites alert possible?

What sort of code?

[yump]

Not sure if this is an html thing...

Would like to warn visitors not to save a page in favourites because its url might change.

Anyone know how to do this please?
ie. pop up alert if they try to add.

[Robin_reala]

Not that I know of, but when you move the page setting a 301 code [w3.org] (or some other 3xx code) on the old URL would be the best bet.

[tedster]

Robin is right -- there is no way to detect when a user bookmarks a page. If there were, we would easily be able to keep statistics on how many favorites were set -- but that just can't be done, unfortunately. It wold be useful information.

[John Carpenter]

There actually is a way to detect that a visitor bookmarked your site. However, there are two limitations:

1) You can detect it only the next time the visitor returns to your site.
2) It works only for the IE browsers.

The trick is simple. If a visitor request the favicon.ico file, he or she has bookmarked your site. Firefox requests this file everytime, while IE only if the URL is in the favorites.

[yump]

Thanks for the comments. Think I'm going to have to do a bit of coding in the pages.

Basically I'm trying to make sure visitors only bookmark the latest date dynamic page of some adverts where the url after the? determines the dates shown. Some of them are saving page 2,3 etc. by accident and then wondering why the adverts are a week out of date when they return.

The basic url is the same, with the stuff after the? changing to modify the dates.

So I was going to put a warning up if they try to bookmark page 2 onwards.

May have to code pages so that if they haven't arrived from our url, the page defaults to page 1.