stargate system lua

sg = peripheral.wrap("stargate_0")
print("STARGATE-OA13-QWU-NL")
print("1.Dial stargate")
print("2.Close stargate")
print("3.Open Iris")
print("4.Close Iris")
choice = read()
if choice==1 then
	print("Gate adress:")
	adress = read()
	sg.dial(adress)
end
if choice==2 then
	sg.disconnect()
end
if choice==3 then
	sg.openIris()
end
if choice==4 then
	sg.closeIris()
end
shell.run("clear")
shell.run("startup")