Untitled

<?php
	session_start();
	$user=false;
	$pass=false;

	if(!isset($_SESSION["username"])){
		if(isset($_POST["username"]))
			if(empty($_POST["username"]))
				echo "inserisci username </br>";
			else{
				$username=$_POST["username"];
				if(strlen($username)<=30)
					$user=true;
				else
					echo "inserire un username di max 30 caratteri </br>";
			}
		if(isset($_POST["password"]))
			if(empty($_POST["password"]))
				echo "inserisci password </br>";
			else{
				$password=$_POST["password"];
				$pass=true;
			}
		if(isset($_POST["nome"]))
			if(empty($_POST["nome"]))
				echo "inserisci nome </br>";
			else{
				$nome=$_POST["nome"];
				if(strlen($nome)<=30)
					$name=true;
				else
					echo "inserire un nome di max 30 caratteri</br>";
			}
		if(isset($_POST["cognome"]))
			if(empty($_POST["cognome"]))
				echo "inserisci cognome </br>";
			else{
				$cognome=$_POST["cognome"];
				if(strlen($cognome)<=30)
					$surname=true;
				else
					echo "inserire un cognome di max 30 caratteri</br>";
			}

		if(isset($_POST["email"]))
			if(empty($_POST["email"]))
				echo "inserisci email </br>";
			else{
				$email=$_POST["email"];
				if(strlen($email)<=128){
					if(filter_var($email, FILTER_VALIDATE_EMAIL))
						$mail=true;
					else
						echo "inserire un'email valida</br>";
				}
				else
					echo "inserire un'email di max 128 caratteri</br>";
			}

		if($user && $pass && $name && $surname && $mail){
			$connessione=mysql_connect("localhost","root","");
			$ris=mysql_query("use sito",$connessione);
			$password=md5($password);
			$ris=mysql_query("insert into utenti(username,nome,cognome,email,password) values('".$username."','".$nome."','".$cognome."','".$email."','".$password."')",$connessione);
			if($ris){
				$_SESSION["username"]=$username;
				$_SESSION["password"]=$password;
				header("location: homepage.php");
			}
			else
				echo "inserire valori validi </br>";
		}
	}//fine if
	else
		header("location: homepage.php");
?>
<!DOCTYPE html>
<html>
<head>
	<title>Registrati</title>
</head>
<body>
	<h1>Registrati</h1>
	<form action="registrati.php" method="POST">
		Inserire username:</br>
		<input type="text" name="username"></br></br>
		Inserire password:</br>
		<input type="password" name="password"></br></br>
		Inserire nome:</br>
		<input type="text" name="nome"></br></br>
		Inserire cognome:</br>
		<input type="text" name="cognome"></br></br>
		Inserire email:</br>
		<input type="text" name="email"></br></br>
		<input type="submit" value="Registrati">
	</form>
	</br>
	<a href="login.php">Sei gia' registrato? Accedi</a>
</body>
</html>