Wi-fi reciever

print("online")
while true do
rednet.open(3)
message == "1"
then
redstone.setOutput("back",true)
sleep(30)
redstone.setOutput("back", false)
end
print("off")
end

Please correct my code

note this is 1.6.4

What exactly are you trying to do? Your title is vague, and you code is not much better.

Are you trying to make a rednet chat system or something of the sort?

I think he is trying to emulate wireless redstone.
corrected ( i think ) code

print( "online" )
rednet.open( "side" ) --#note, sides are not numaric.  "right", "left", "top", etc.
while true do
 local id, message = rednet.receive() --#recieve a message from the rednet
 if message == "1" then  --#I assume you sent "1", not 1, since 1 ~= "1"
  print( "on" )
  rs.setOutput("back", true)
  sleep( 30 ) --#pause for 30 seconds
  rs.setOutput("back", false)
 end
 print( "off" )
end