function findModem()
    for _,s in ipairs(rs.getSides()) do
        if peripheral.isPresent(s) and peripheral.getType(s) == "modem" then
            return s
        end
    end
    return false
end

if pocket then
    rednet.open("back")
    tArgs = { ... }
    if #tArgs ~= 2 then
        print("Usage: " .. shell.getRunningProgram() .. " <to> <message>")
    else
        rednet.broadcast("_FIND")
        while true do
            id, msg, dis = rednet.receive()
            if id == msg then
                message = tArgs[2]
                to = tArgs[1]
                rednet.send(id, { to = to, message = message })
                break
            end
        end
    end
else
    while true do
        rednet.open(findModem())
        id, msg, dis = rednet.receive()
        if type(msg) == "table" and msg.to and msg.message then
            commands.exec("msg " .. msg.to .. " " .. msg.message)
        else
            if msg == "_FIND" then
                rednet.send(id, os.getComputerID())
            end
        end
    end
end