[Lua] [error] rednet:327: string expected

Hello there.

Previously I had been running my program "melons" to harvest melons from my farm and then drop them off. This was running fine without errors

From this I wanted all my turtles controlled by a central computer:

Turtle Code:

print("Waiting for commands...")
rednet.close()
  rednet.open()
senderID, mes, dis = rednet.receive()
if senderID==32 and mes=="start" then
  dofile(melons)
end

Computer Code:

rednet.close("top")
  rednet.open("top")
	rednet.broadcast("start")

The turtle prints then comes up with the error in the title.

Please Help Thanks in advance

EDIT: I am using the Tekkit modpack on a server,although I am the server owner.

I think you need to designate a side for open. On a turtle, just use rednet.open("right").

That doesn't appear to work.
Thanks for suggesting though.

He's correct. If it's not right, try left. Either way, you need to specify the side that the modem is on. You did craft a modem on to it, right?

Wireless turtles usually have their modems on the right

Ok, sorry about this. i derped and forgot that "right" has to be in quotation marks *faceplam*

Ok, that errors gone but now the turtle wont carry out the program. No errors are shown.

EDIT: shell.run() doesnt work…

You don't have melons in quotes either.

Thanks everyone for your help, after fiddling about I got it to work.