Help plz

const Discord = require("discord.js");

const TOKEN = "BotTokenHere";
const PREFIX = "e!";

var bot = new Discord.Client();

bot.on("ready",function() {
    console.log("Ready!");
})

bot.on("message", function(message) {
    if (message.author.equals(bot.user)) return;

    if (message.content.startsWith(PREFIX)) return;

    var args = message.content.substring(PREFIX.length).split(" ");

    switch (args[0]) {
        case "ping":
            message.channel.sendMessage("Pong!");
            break;
    }
});

bot.login(TOKEN);