Turn URL's into hyperlinks in ASP.NET

Today, I needed a function that would look through some text input and check for any URL's and the URL's should then be turned into hyperlinks. In other words, I had to turn this www.someurl.com into <a href="http://www.someurl.com" target="_blank">www.someurl.com</a>. It should also be able to handle URL's that starts with http:\\ and not just www.