About four years ago, I wrote an article for WebReference entitled, Creating a Cross-Browser (DOM) Expandable Tree. At the time, the DOM was still fairly new and Netscape Navigator 4.7 was still in use by many people, so I got a lot of questions such as, “how can I make this work in Netscape?” My answer was that you couldn’t, and I refused to figure out a way to do it because I believed that the DOM was the future. This was a fairly popular article at the time.

Recently, I received an email from someone pointing out that the tree didn’t work in the latest version of Opera. Having not looked at this code in about three years, I decided it would be fun to revisit it. I was able to figure out the problem (Opera didn’t like setAttribute() to set an element’s ID), and low and behold, this four-year-old code still works in all DOM-compliant browsers! I’ve updated the code and it can be downloaded in the Downloads section.