NAME
	send_message - send a message to a user

SYNOPSIS
	int send_message(string message)
	int send_message(int echo)


DESCRIPTION
	In the first form, send a message to the user associated with the
	current object.  In the second form, user input echoing will be
	turned off or on, the value of echo being zero or non-zero,
	respectively.  Used by the driver object, send_message() will write
	the message on stderr.
	For binary connections, send_message() will return the length of the
	string if it could be sent right away, a number indicating how much of
	the string could be sent immediately, or -1 otherwise.  If only part of
	the string could be sent initially, message_done() will be called in
	the user object when the remainder has also been sent.  If
	send_message() is used to send new data before all of the pending data
	from a previous call has been sent, the pending data is discarded.
	For telnet connections, send_message() will always return the length
	of the string sent.

NOTES
        This kfun is only active when the network extensions are enabled.
        See send_message when not using the network extensions.
SEE ALSO
	kfun/query_ip_number, kfun/this_user, kfun/users