How do I remove the port number from a URL in C#.NET?

Regular Expression:

:{1}\d*

Using C#.NET, the above regular expression can be applied to a URL to strip the port number (along with ":"):

Regex regex = new Regex( @":{1}\d{1,}" );
string url = regex.Replace( "http://andrewgunn.blogspot.com:81/", string.Empty );

Port numbers

http://www.iana.org/assignments/port-numbers