var socket = io();

socket.on("connect", () => {
  button.addEventListener("click", function() {
     socket.emit("send", {room, message, client1_id, client2_id});
  })
})

var socket = io();

socket.on("connect", () => {
  socket.emit("send_id", (socket.io.engine.id))
  socket.on(client2_id, (data) => {
    console.log(data);
  })
})

var tech = io.of("/");

tech.on("connection", (socket) => {
  var receiver_id;
  socket.on("send_id", (data) => {
    receiver_id = data;
  })
  socket.on("send", data => {
    io.to(receiver_id).emit(data.client2_id, "hello");
  })
})