Convert Relative Paths to Absolute Using Regular Expressions

I ran into a situation where I needed to screen scrape some content from a site and display it on my own site. This works really well except for dependent files like javascripts, SWFs and images that had src attributes with relative paths. So I figured it wouldn't be that hard to create a helper method to find and replace them using Regular Expressions. So here it is:

public static String ConvertRelativePathsToAbsolute(String text, String absoluteUrl)
{
	String value = Regex.Replace(text,
		"<(.*?)(src|href)=\"(?!http)(.*?)\"(.*?)>",
		"<$1$2=\"" + absoluteUrl + "$3\"$4>",
		RegexOptions.IgnoreCase | RegexOptions.Multiline);
	
	// Now just make sure that there isn't a // because if
	// the original relative path started with a / then the
	// replacement above would create a //.

	return value.Replace(absoluteUrl + "/", absoluteUrl);
}

Sample Usage:

String html = "<p><img src=\"images/dot.gif\" alt=\"test\" /></p>";
String baseUrl = "http//www.nontalk.com/";
String replacedHtml = ConvertRelativePathsToAbsolute(html, baseUrl);
// replacedHtml => <p><img src="http://www.nontalk.com/images/dot.gif" alt=\"test\" /></p>