common.js

 var users = localStorage.getItem("usersDB");
  users = JSON.parse(users);
  if (users === null)
     var users = [];

  function Create() {
    var person = JSON.stringify({
      fullname: document.getElementById('fullname').value,
      username: document.getElementById('username').value,
      oracleid: document.getElementById('oracleid').value,
      email: document.getElementById('email').value,
      phone: document.getElementById('phone').value,
      jobtitle: document.getElementById('jobtitle').value,
      location: document.getElementById('location').value,
      password: document.getElementById('newpassword').value
    });
    users = getJSON();
    users.push(JSON.parse(person));
    localStorage.setItem("usersDB", JSON.stringify(users));
    postJSON(localStorage.getItem("usersDB"));
    return true;
  }

  function getJSON(){
    var resp ;
    var xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function() {
        if (this.readyState == 4 && this.status == 200) {
          resp = this.responseText;
        }
    };
    xhttp.open("GET", "../json/users.json", false);
    xhttp.send();
    return JSON.parse(resp);
  }

   function postJSON(data){
     var xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function() {
        if (this.readyState == 4 && this.status == 200) {

        }
    };
    xhttp.open("POST", "/jsonhandler" , true);
    xhttp.setRequestHeader("Content-Type", "application/json");
    xhttp.send(data);
  }

   document.getElementById('btn-signup').addEventListener('click', Create);
 /* function Edit() {
    tblPersons[selected_index] = JSON.stringify({
        ID: $("#txtID").val(),
        Name: $("#txtName").val(),
        Phone: $("#txtPhone").val(),
        Email: $("#txtEmail").val()
    });
    localStorage.setItem("tblPersons", JSON.stringify(tblPersons));
    alert("Los datos han sido editados"); //Mensaje de alerta
    return true;
  }

  function Delete() {
    tblPersons.splice(selected_index, 1);
    localStorage.setItem("tblPersons", JSON.stringify(tblPersons));
    alert("Persona Eliminada");
  }*/

 /* function List() {
    $("#tblList").html("");
    $("#tblList").html(
            "<thead>" +
            "<tr>" +
            "<th>ID</th>" +
            "<th>Nombre</th>" +
            "<th>Teléfono</th>" +
            "<th>Email</th>" +
            "<th>Acciones</th>" +
            "</tr>" +
            "</thead>" +
            "<tbody>" +
            "</tbody>"
            );
    for (var i in tblPersons) {
        var per = JSON.parse(tblPersons[i]);
        $("#tblList tbody").append("<tr>" +
                "<td>" + per.ID + "</td>" +
                "<td>" + per.Name + "</td>" +
                "<td>" + per.Phone + "</td>" +
                "<td>" + per.Email + "</td>" +
                "<td><img src='edit.png' alt='Edit" + i + "' class='btnEdit'/>&nbsp &nbsp<img src='delete.png' alt='Delete" + i + "' class='btnDelete'/></td>" +
                "</tr>"
                );
    }
  }
*/
    //if (operation === "C")
        //return Create();
    //else
      //  return Edit();
  //});

 // List();

 /* $(".btnEdit").bind("click", function () {
    operation = "E"; //"E" = Editar
    selected_index = parseInt($(this).attr("alt").replace("Edit", ""));
    var per = JSON.parse(tblPersons[selected_index]);
    $("#txtID").val(per.ID);
    $("#txtName").val(per.Name);
    $("#txtPhone").val(per.Phone);
    $("#txtEmail").val(per.Email);
    $("#txtID").attr("readonly", "readonly");
    $("#txtName").focus();
  });*/

 /* $(".btnDelete").bind("click", function () {
    selected_index = parseInt($(this).attr("alt").replace("Delete", ""));
    Delete();
    List();
  });*/