procedure SendRedirect(const NewLocationURL: String; const
      Content: String=''; StatusCode: Integer=HTTP_FOUND; const
      StatusMessage: String='Redirecting')

Sends a redirect response to the client browser using the passed new location, content, HTTP status code and message. The Unicode content is automatically sent in UTF-8 format.

Please see the following link for a complete list of HTTP status/error codes:

Status Code and Reason Phrase