At my place of employment, we are beginning to plug in international support to our websites. Our clients have gotten used to dynamic number formatting in applications such as Excel. Naturally, we need to duplicate this functionality in our web pages. In many areas, we'll be using the globalization features of Microsoft.NET. Unfortunately, many of our pages have client side functionality that isn't well suited for server controls. So, I was left to come up with a way to format numbers 100% client side in JavaScript. The code sample below is the result of my work.