diff --git a/main.php b/main.php
index 146237b..ac913a3 100644
--- a/main.php
+++ b/main.php
@@ -1,28 +1,11 @@
 <?php	
 	require './credentials.php';
 	require './php/utils.php';
-	
-	$credentials = new Credentials();
-	$usersdb = $credentials->usersdb;
-	$mortsdb = $credentials->mortsdb;
+	require_once('./php/security.php');
 	
 	date_default_timezone_set("Europe/Madrid");
 	
-	$user = $_COOKIE['user']; // (int)$_POST['user'];
-	$password = $_COOKIE['password']; // isset($_POST['password']) ? md5($_POST['password']) : '';
-
-	if (!isset($_COOKIE['user']) or $_COOKIE['user'] == '') {
-		die("<script>window.location.href = './'</script>");
-	} else if (isset($_COOKIE['password'])) {
-		$query_password = "SELECT password FROM $usersdb WHERE id=$user";
-		if (query($query_password)->fetch_row()[0] != $password) {
-			// Unset variables
-			setcookie('user', '', -1, "/");
-			setcookie('password', '', -1, "/");
-			
-			die("<script>window.location.href = './?passwordchanged=1'</script>");
-		}
-	}
+	Security::checkIsSignedIn();
 ?>
 <html>
 	<head>
@@ -51,11 +34,11 @@
 		<script src="./js/animations.js"></script>
 
 		<?php
-			$user = get_users($user);
+			$user = get_users($_SESSION["id"]);
 			$victim = get_users($user->quimata);
 			if ($user->mort) die("<script>window.location.href = './dead.php'</script>");
 			
-			$bits = dec2bits($user->bits);	
+			$bits = dec2bits($user->bits);
 			$bit_counter = 0;
 		?>
 
@@ -66,7 +49,7 @@
 				'requested': <?=(int)$user->requested?>,
 				'mort': <?=(int)$user->mort?>,
 
-				'nom': "<?=$user->nomcomplet?>",
+				'nom': "<?=Security::htmlsafe($user->nomcomplet)?>",
 				'curs': <?=(int)$user->curs?>,
 				'grau': <?=(int)$user->grau?>
 			};
@@ -77,12 +60,12 @@
 		<div id="outter-container">
 			<div id="inner-container">
 				<a href="./" class="goback">Canvi d'usuari</a><br />
-				<h2>Hola <name id="user_name"><?=$user->nom()?></name>,</h2>
+				<h2>Hola <name id="user_name"><?=Security::htmlsafe($user->nom())?></name>,</h2>
 
 				<div class="formulari_contrasenya">
 					<p>Sembla que no tens clau d'accés, la gent podrà entrar al teu compte...</p>
 					<form action="./php/change_password.php" method="POST">
-						<input type="hidden" value="<?=$user->id?>" name="userid">
+						<input type="hidden" value="<?=(int)$user->id?>" name="userid">
 						<input type="password" placeholder="Nova clau d'accés..." name="password" /><br />
 						<input type="password" placeholder="Repeteix la clau d'accés" name="confirmation"/><br />
 						<input type="submit" value="Posar clau d'accés">
@@ -110,11 +93,11 @@
 								</div>
 							</td>
 							<td class="table_text">
-								<div id="victim_name"><?=$victim->nomcomplet?></div>
+								<div id="victim_name"><?=Security::htmlsafe($victim->nomcomplet)?></div>
 								<div id="victim_curs_i_grau">
-									<span id="victim_curs"><?=$victim->nomcurs()?></span>
+									<span id="victim_curs"><?=Security::htmlsafe($victim->nomcurs())?></span>
 									-
-									<span id="victim_grau"><?=$victim->nomgrau()?></span>
+									<span id="victim_grau"><?=Security::htmlsafe($victim->nomgrau())?></span>
 								</div>
 								<div id="butons" class="options">
 									<button id="win" onclick="js: send_request(user, 'REQ KILL');">L'he matat</button>
@@ -125,10 +108,10 @@
 				</div>
 				
                                 <?php
-                                        $query_seen_victim = "SELECT COUNT(*) FROM missatges WHERE `seen` = 0 AND (`receiver_id` = " . $user->id . " AND `sender_id` = " . $user->quimata . ")";
-                                        $query_seen_killer = "SELECT COUNT(*) FROM missatges WHERE `seen` = 0 AND (`receiver_id` = " . $user->id . " AND `sender_id` != " . $user->quimata . ")";
+                                        $query_seen_victim = "SELECT COUNT(*) FROM missatges WHERE `seen` = 0 AND (`receiver_id` = " . (int)$user->id . " AND `sender_id` = " . (int)$user->quimata . ")";
+                                        $query_seen_killer = "SELECT COUNT(*) FROM missatges WHERE `seen` = 0 AND (`receiver_id` = " . (int)$user->id . " AND `sender_id` != " . (int)$user->quimata . ")";
                                 ?>
-                                
+
 				<div>
 					<p>Podeu posar aquesta pàgina com a icona apretant el botó de "Add to Home Screen" del vostre navegador.</p>
 					<a href="./ranking.php">Anar al rànquing</a><br />