Node.js Reference Error: Class is not defined -

i writing module exports few functions. created file calls module cant seem file reference class created in module. im not sure im doing wrong. here code.

 var eventemitter = require('events').eventemitter;  var inherits = require('util').inherits;     var employeeemitter = function(){}  function employeeemitter(data){   eventemitter.call(this);  }             inherits(employeeemitter, eventemitter);      employeeemitter.prototype.lookupbylastname = function(data, lastname)  {var lname = _.where(data, {lastname: lastname});  console.log(colors.red('lookup last name: ' + (lastname)));  console.log(colors.blue('event lookupbylastname raised! '+ lastname));  console.log(lname);   };   employeeemitter.prototype.lookupbyid=function(data, id){  console.log(colors.red('lookup id: ' +id));  console.log(colors.blue('event lookupbyid'));     id = _.findwhere(data, {id: id });  console.log(id);  };   module.export = employeeemitter;    

this file using call above module

  var employeeemitter = require('./employeeemitter.js');   data = [   {id:1, firstname: 'john', lastname: 'smith'},   {id:2, firstname: 'jane', lastname: 'smith'},   {id:3, firstname: 'john', lastname: 'doe'}    ];    var employeeemitter = new employeeemitter(data);   employeeemitter.on('event1', function(data) {   });      employeeemitter.lookupbylastname(data, 'smith');   employeeemitter.addemployee(data, 'william', 'smith');   employeeemitter.lookupbylastname(data, 'smith');   employeeemitter.lookupbyid(data, 2); 

when call file get: reference error employeeemitter not defined