bios:366: [string "turtleon2"] :2: ')' expected

I was trying to create a program for my pocket computer that would allow me to activate a mining turtle over rednet.
The pocket computer is supposed to send a signal to the turtle and then the turtle is supposed to send a signal to the pocket computer.
But so far i'm having problems with this error. can anyone tell me what i am doing wrong?

Here is the code for the pocket computer.

rednet.open("back")
rednet.send(19 "turtlestart")
print("waiting for turtle response")
id,message = rednet.receive()
if id == 19 and message == "ping" then
print("The turtle has started.")
end
rednet.close("back")

Sorry if my english is bad, it is not my primary language.

rednet.send(19, "turtlestart")

You are missing a ',' on line two inbetween 19 and 'turtlestart'

Thanks.
It works now. sorry for wasting your time. I should have been more thorough when i searched for the error.