Code:
new duration,holdtime,fadetype,red,green,blue,alpha
message_begin(MSG_ONE,get_user_msgid("ScreenFade"),{0,0,0},id) //id = player index.
write_short(duration)
write_short(holdtime)
write_short(fadetype)
write_byte(red)
write_byte(green)
write_byte(blue)
write_byte(alpha)
message_end()
Just define them all.