It's worthwhile to keep in mind that there are many different browsers around, and your Web applications should be tested in the ones you want to support.

As of this writing, Internet Explorer and Firefox make up about 96 percent of browser use, and the rest (Opera, Safari, Mozilla, and so on) are each in the 1 percent or less category.

And don't forget that not all browsers will support JavaScript, or will have JavaScript turned on. For those users, you should have a backup plan, such as a streamlined version of your site that's built in tables.