My monitor isn't functioning.

Title: My monitor isn't functioning.
I have a program:

rednet.open("right")
monitor=peripheral.wrap(left)
monitor.setTextScale(1)
while true do
message = rednet.receive()
monitor.write(message)
end

But when I try broadcasting ay message, my monitor just writes 3,0. What to do?

rednet.receive returns both the ID of the computer that sent the message, the message itself, and even the distance between the two computers. You can easily get the message using a dummy variable:

local _, message = rednet.receive()