diff --git a/assets/js/charts.js b/assets/js/charts.js
index 00b12cd..9f17df1 100644
--- a/assets/js/charts.js
+++ b/assets/js/charts.js
@@ -3,12 +3,14 @@ import $ from "jquery";
 
 let delta = 'M';
 let graph_type = "sum_invoices";
-let time = 7;
+let time = 365;
 let is_count = true;
 let chart = null;
+let prev_chart = null;
+let pie_chart = null;
 
 function lineChart(label_values, result){
-    if(chart != null){
+    if (chart != null) {
         chart.destroy();
     }
 
@@ -27,10 +29,14 @@ function lineChart(label_values, result){
 }
 
 function barChart(label_values, data){
+    if (prev_chart != null) {
+        prev_chart.destroy();
+    }
+
     $("#progress").hide();
     $("#prevision").show();
 
-    new Chart(document.getElementById("lineChartPrevisions"), {
+    prev_chart = new Chart(document.getElementById("lineChartPrevisions"), {
         type: 'bar',
         data: {
             labels: label_values,
@@ -48,9 +54,13 @@ function barChart(label_values, data){
 }
 
 function pieChart(costs, earnings) {
+    if (pie_chart != null) {
+        pie_chart.destroy();
+    }
+
     $("#pieChartError").hide();
 
-    new Chart(document.getElementById("pieChart"), {
+    pie_chart = new Chart(document.getElementById("pieChart"), {
         type: 'doughnut',
         responsive: true,
         mantainAspectRatio: false,
@@ -160,7 +170,7 @@ function graphicTotals(data) {
             gains = data.gains_values[index];
         }
     });
-    
+
     pieChart(costs, gains);
 }
 
diff --git a/lib/infin/companies.ex b/lib/infin/companies.ex
index 4fcccbb..66e9cea 100644
--- a/lib/infin/companies.ex
+++ b/lib/infin/companies.ex
@@ -55,7 +55,10 @@ defmodule Infin.Companies do
   """
   def get_company_by_nif!(nif), do: Repo.get_by!(Company, nif: nif)
 
-  def get_company_by_nif(nif), do: Repo.get_by(Company, nif: nif)
+  def get_company_by_nif(nif) do
+    query = from(c in Company, where: c.nif == ^nif, preload: :users)
+    Repo.one(query)
+  end
 
   @doc """
   Creates a company.
diff --git a/lib/infin_web/controllers/budget_controller.ex b/lib/infin_web/controllers/budget_controller.ex
index a61d342..b06aba5 100644
--- a/lib/infin_web/controllers/budget_controller.ex
+++ b/lib/infin_web/controllers/budget_controller.ex
@@ -47,6 +47,12 @@ defmodule InfinWeb.BudgetController do
 
     budget_params = Map.replace!(budget_params, "value", value)
 
+    if is_nil(budget_params["category_id"]) do
+      conn
+        |> put_flash(:error, "Please associate a category to the budget.")
+        |> redirect(to: Routes.budget_path(conn, :new))
+    end
+
     budget_params =
       Map.replace!(
         budget_params,
diff --git a/lib/infin_web/controllers/user_registration_controller.ex b/lib/infin_web/controllers/user_registration_controller.ex
index c108b04..0640dfe 100644
--- a/lib/infin_web/controllers/user_registration_controller.ex
+++ b/lib/infin_web/controllers/user_registration_controller.ex
@@ -4,6 +4,7 @@ defmodule InfinWeb.UserRegistrationController do
   alias Infin.Accounts
   alias Infin.Accounts.User
   alias InfinWeb.UserAuth
+  alias Infin.Companies
 
   def new(conn, _params) do
     changeset = Accounts.change_user_registration(%User{})
@@ -11,6 +12,25 @@ defmodule InfinWeb.UserRegistrationController do
   end
 
   def create(conn, %{"user" => user_params}) do
+    company = Companies.get_company_by_nif(user_params["company"]["nif"])
+    if (not is_nil(company)) and company.users == []  do
+      user_params = Map.put(user_params, "company_id", company.id)
+      case Accounts.add_user(user_params) do
+        {:ok, user} ->
+          {:ok, _} =
+            Accounts.deliver_user_confirmation_instructions(
+              user,
+              &Routes.user_confirmation_url(conn, :confirm, &1)
+            )
+
+          conn
+          |> put_flash(:info, "User created successfully.")
+          |> UserAuth.log_in_user(user)
+
+        {:error, %Ecto.Changeset{} = changeset} ->
+          render(conn, "new.html", changeset: changeset)
+      end
+    end
     case Accounts.register_user(user_params) do
       {:ok, user} ->
         {:ok, _} =
diff --git a/lib/infin_web/live/dashboard/graph.html.leex b/lib/infin_web/live/dashboard/graph.html.leex
index ef6cafe..7b5043b 100644
--- a/lib/infin_web/live/dashboard/graph.html.leex
+++ b/lib/infin_web/live/dashboard/graph.html.leex
@@ -39,7 +39,7 @@
     <div class="column">
       <div class="tile is-child box">
         <div class="is-info is-light has-text-centered" style="height: 450px">
-          <p class="is-size-4">Year Costs and earnings</p>
+          <p class="is-size-4">Year Costs and Earnings</p>
           <hr>
           <div class="chart-container is-inline-block">
             <p id="pieChartError"> No data available </p>