How do I generate a Friendly URL in C#?

if (String.IsNullOrEmpty(title)) return "";

// remove any leading or trailing spaces left over
… muuuch later:
// remove trailing dash, if there is one

// replace spaces with single dash
title = Regex.Replace(title, @"s+", "-");
// if we end up with multiple dashes, collapse to single dash
title = Regex.Replace(title, @"-{2,}", "-");

// make it all lower case
title = title.ToLower();
// remove entities
title = Regex.Replace(title, @"&w+;", "");
// remove anything that is not letters, numbers, dash, or space
title = Regex.Replace(title, @"[^a-z0-9-s]", "");
// replace spaces
title = title.Replace(' ', '-');
// collapse dashes
title = Regex.Replace(title, @"-{2,}", "-");
// trim excessive dashes at the beginning
title = title.TrimStart(new [] {'-'});
// if it's too long, clip it
if (title.Length > 80)
    title = title.Substring(0, 79);
// remove trailing dashes
title = title.TrimEnd(new [] {'-'});
return title;

if (String.IsNullOrEmpty(title)) return "";

// remove entities
title = Regex.Replace(title, @"&w+;", "");
// remove anything that is not letters, numbers, dash, or space
title = Regex.Replace(title, @"[^A-Za-z0-9-s]", "");
// remove any leading or trailing spaces left over
title = title.Trim();
// replace spaces with single dash
title = Regex.Replace(title, @"s+", "-");
// if we end up with multiple dashes, collapse to single dash
title = Regex.Replace(title, @"-{2,}", "-");
// make it all lower case
title = title.ToLower();
// if it's too long, clip it
if (title.Length > 80)
    title = title.Substring(0, 79);
// remove trailing dash, if there is one
if (title.EndsWith("-"))
    title = title.Substring(0, title.Length - 1);
return title;

new Regex("[^a-zA-Z-_]").Replace(s, "-")

a = a.Replace(' ', '-');