I have problems with nodejs + ajax + cassandra

I have the following problem:  I'm trying to develop an App, with Nodejs + cassandra, but inside a form that I have, when calling an ajax method which is inside the same form (.jade) it gives me an error here is the code:

script.

 function ajaxejecutar() {
     'use strict';
        var agencia = document.addagencyform.nombagency.value;
        $.ajax({           
           contentType: "application/json; charset=UTF-8",
           datatype: "JSON",
           data: {agencia:agencia},
           url: "/runnerapp/querylib/queryagency",
           async: true,
           beforeSend: function () {
              $('#nombagency').val('Buscando...');
            },
            success: function (res) {
               console.log(resp);
               console.log(' Agencia existe');
            },
            error: function (jqXHR, status, error) {
               console.log(' error en el metodo AJAX');
               console.log(' estado del error: ' + JSON.stringify(status));
               console.log(' valor del error: ' + error);
               console.log(' valor jqXHR: ' + JSON.stringify(jqXHR));
               console.log(' valor de la agencia: ' + agencia);
            },
            timeout: 10000
        })        
     }

and this is the .js file that should be processed:

'use strict';
var cassandra = require('cassandra-driver'),
express = require('express'),
router = express.Router(),
agencia = document.getElementById('nombagency').value,
client = new cassandra.Client({contactPoints:['127.0.0.1']});
client.connect(function (err, result) {
  if (err) {
    console.log('error al conectarse en consulta ajax: '+err);
  } else {
     console.log('conectado a consulta jquery...'+result);
  }  
  });
var getdetails ='SELECT * FROM runnerks.agency WHERE nombagency = ?';
router.get('/dashboard/addagency', function(req, res, next) {
    client.execute(getdetails, [req.params.nombagency], function(err, result)     
      {
         if (err) {
            res.status(404).send({msg: err});
            console.log('error en consulta...');
         } else {
            console.log('la agencia existe: '+result);       
         }
      }); 
  });
module.exports = router;

If someone could help me I would greatly appreciate it.

Note: I send to print with a console.log and I always get the same error: GET / runner / querylib / queryagency? Agency = Agency ABC 500 80.242 ms - 1149