title: ldapjs authentication error
body: <p>My company has a ldap server, I try to test the ldap connection using nodejs with ldapjs module, I just want to test the connection at the first place, so no search function is included.</p>
  
  <p>here is the code:</p>
  
  <pre><code>exports.authenticate = function(req, res){
    var ldap = require('ldapjs');
    var username = req.body.username;
    var password = req.body.password;
  
    var client = ldap.createClient({
      url: 'LDAP://192.168.3.220/'
    });
  
    client.bind(username, password, function (err) {
      if(err){
        res.send(err);
      }else{
        res.send('login');        
    });
  };
  </code></pre>
  
  <p>when I input correct username and password, it sends back "login", which is expected.
  when I input correct username but wrong password, it sends back the err object, which is also expected.</p>
  
  <p>here is the problem:
  when I input valid username or invalid username (such as "fjdkfjdklsjfsjd") without password, it also sends back "login", which is abnormal.</p>
  
  <p>I am new to ldap and ldapjs, so it might be just a simple mistake but I could not figure it out. Please help....</p>