My Celluar System programs exit's by itself when i try to send a text

term.clear()
print("Cell Service Active")
rednet.open("top")
id, message = rednet.receive()
if message == "ticketadd" then
   print("Please put in ticket. Press Enter to continue")
   enter = read()
   if fs.exists("/disk/blahblah") then
   print("Vaild, Adding Data...")
   shell.run("mkdir",id)
   local file = fs.open("/",id,"/Data","w")
   file.writeLine("300MB")
   file.close()
   os.reboot()
   end
if message == "sendtext" then
   if fs.exists("/",id) == true then
	  rednet.send(id, "activated")
   else
	  rednet.send(id, "noactivated")
  
end
end
end