That being said, if you can believe www.w3schools.com browser stats, they are showing Mozilla based browsers at 21.2%% and Netscape 7 at 1.2%. I don't know why they would report Netscape as different from Mozilla. Netscape 7 is built on Mozilla, and so are a number of other browsers, application suites and development tools. You can find a good list here.

With Mozilla/Firefox/Netscape popularity growing, this means a possibility that a lot of people visiting your site will not be able to see popup windows if you are using them.

With the release of Service Pack 2 for XP users, Internet Explorer can block certain popups. As a matter of fact, when the service pack is installed the popup blocker is turned on by default. For reference please see this Microsoft page.

This doesn't mean it will block requested javascript windows, but unrequested popups will be blocked. These are often used to contain a departing message to the user.

Some people have also reported that if SP2 users set their security settings to high, that it will also block links that use "target="_blank" to open new windows. I don't have any way of testing the validity of this statement. If you would like to email me and tell me it is true, it would be much appreciated.

So how can you get around this?

John Watson wrote a small Perl script that will help. Once this script is installed... if a user clicks on an external link on your site, it loads a temporary webpage telling them they will be re-directed in X seconds. Then you can have a link to your newsletter sign-up page (or any other page), so if they click your link it cancels the external click and brings them back to you. You can grab a copy of this script here.

Then you will need to edit the links pointing to external sources on your site like this:

<a href="/cgi-bin/redir.pl?url=http://somedomain.com/index.html&title=TITLE OF LINK">URL Title</a>

If you look through the Perl Code you will see a few references to "print <<EOT;" and these are the areas you can edit to make the redirect page look similar to your website if you want to. Or... it might be an nice idea to make it look a little different -- just whatever you prefer.