The SendError method sends a response to the
client indicating that an error has occurred, providing a numeric
error code and HTML formatted text which may be displayed to the user.
The Message parameter should provide a brief description of
the error that will be included in the output sent to the client. Note
that the message should not contain any special formatting control
characters or HTML markup.
This method provides a simplified interface for sending an error
response to the client. In some cases, a browser may choose to display
its own error message to the user in place of the generic HTML
document generated by this method. If you want your application to
send a customized HTML document for a specific type of error, you
should use the SendResponse method.
If you wish to redirect the client to use an alternate URL to
access the requested resource, it is recommended that you use the
RedirectRequest method rather than sending an error response.