Note   IIS 6.0 on Windows Server 2003 has functionality equivalent to URLScan built in.

Response.Write(
	HttpUtility.HtmlEncode(Request.Form["name"])
	);

• {} specifies a named Unicode character class.
• \p{} matches any character in the named character class specified by {}.
• {L} performs a left-to-right match.
• {Lu} performs a match of uppercase.
• {Ll} performs a match of lowercase.
• {Zs} matches separator and space.
• {1,40} means no less that 1 and no more than 40 characters.
• {Mn} matches mark and non-spacing characters.
• {Zs} matches separator and space.
• * specifies zero or more matches.
• $ means stop looking at this position.

using System.Text.RegularExpressions;
. . .
private void Page_Load(object sender, System.EventArgs e)
{
  // Name must contain between 1 and 40 alphanumeric 
  // characters together with (optionally) special 
  // characters '`´ for names such as D'Angelo
  if (!Regex.IsMatch(Request.Form["name"], 
             @"^[\p{L}\p{Zs}\p{Lu}\p{Ll}]{1,40}$"))
      {
      throw new ArgumentException(
           "Invalid name parameter");
      }
  // Use individual regular expressions to validate 
  //other parameters
  . . .
}