add <a href> tag to url

Question

Hi, I need some help with regular expression for the issues as below. There are two scenarios for this 1. I want to add a tag to whatever url without an tag. Meaning if user enters http://www.asp.net, I would like that to be converted to http://www.asp.net 2. If the user already has entered with tag then I would like to retrieve the url. Suppose the url has entered http://www.asp.net, then I want http://www.asp.net irrespective of whether the user has entered spaces before and after = sign and/or has typed the url in quotes or not. That is everything after the href tag. Any guidance or help in this matter would be highly appreciated. Thanks in advance. Murali.