For a simple application such as that I dont think any language/ framework is naturally going to be massively better than the next to do it. Personally would use asp.Net but then that is our prefered framework.
Coldfusion is good for making simple apps, if you want something you can build on in the future I would recommend ASP.Net.
A few more reasons to use ASP.Net are - ASP.Net AJAX : create ajax apps without writing a single line of JavaScript - Visual Studio 2008 : has great debugging and autocomplete features - LINQ : easily query against SQL, XML, or any other data source with a common syntax