Client not receiving emission from server socket.io

Question

I'm trying to make an online multiplayer game with express, socket.io, and nodejs. This is my first time using nodejs, and my first time asking a question so if I do anything wrong please tell me. The problem is happening in the sign in part. I've figured out that the client isn't responding to a server emission. I've looked at this question, Socket.IO server not receiving message from client but it didn't help.

This is the relevant server code:

var io = require('socket.io')(serv,{});
io.sockets.on('connection', function(socket) {
    socket.id = Math.random();
    SOCKET_LIST[socket.id] = socket;

    socket.on('signIn',function(data){
        if(data.username === 'bob' && data.password === "asd"){
            Player.onConnect(socket);
            socket.emit('signInResponse',{success:true});
            console.log('got this far')
        }else {
            socket.emit('signInResponse',{success:false});
        }

    })

This is the relevant client code:

<script>
    var socket = io();
    //sign
    var signDiv = document.getElementById('signDiv');
    var signDivUsername = document.getElementById('signDiv-username');
    var signDivSignIn = document.getElementById('singDiv-singIn');
    var signDivSignUp = document.getElementById('signDiv-singUp');
    var signDivPassword = document.getElementById('signDiv-password');

    signDivSignInfunc = function(){
        console.log('it started')
        socket.emit('signIn',{username:signDivUsername.value,password:signDivPassword.value});
    }
    socket.on('signInResponse',function(data){
        console.log('almost there')
        if(data.success){
            signDiv.style.display = 'none';
            gameDiv.style.display = 'inline-block';
            console.log('worked')
        }else
            alert('Sign in unsuccessful');
    })

Help would be greatly appreciated, thank you.