codice:
<? 
session_start(); 
session_register("loggato"); 
session_register("logout"); 
$logout = $_POST['logout']; 
session_register("nick"); 
$nick = $_POST['nick']; 
session_register("psw"); 
$psw = $_POST['psw'];?> 

<head> 
<link href="css/moduliarial.css" rel="stylesheet" type="text/css"> 
<base target="_self"> 
</head> 

<body bottommargin="0" leftmargin="0" marginheight="0" marginwidth="0" rightmargin="0" topmargin="0" text="#FFFFFF" bgcolor="#000000" > 
<p align="center" style="line-height: 150%"> 

<?php
  $conn=mysql_connect("localhost","root","") or die ("Non riesco a connettermi al database");
  $db=mysql_select_db("user",$conn) or die ("Non trovo il database specificato"); 
  //ok connesso al db, eseguo query
  $query="SELECT * FROM `anagrafica`where `nick`='" .$_SESSION['nick']. "' and psw='" .$_SESSION['psw']. "'";
  $risultato=mysql_query($query,$conn) or die("Interrogazione al database fallita");
  
  //query eseguita con successo, ripesco il risultato
  while ($row = mysql_fetch_array($risultato)) { 
    echo "$row[Cognome] - $row[Nome] - $row[email]-$row[Telefono] - $row[CAP] - $row[Indirizzo]"; 
  }
 
  if (isset($_POST['nick'])and isset($_POST['psw'])) { 
    $loggato=1;
    // devi registrare loggato?
    //session_register('loggato');?
  }
  
  if ($_SESSION['logout']<>"") {
    unset($_SESSION['loggato']);
    session_destroy(); 
  }
  
  if ($_SESSION['loggato']==1) { 
   //è il form per il logout?
?> 
sei loggato 
<td align="center"> 
<form method="post" action="login.php"> 
<input name="logout" class="bottone" type="submit" value="Logout"> 
</form></td> 

<?php
  }  //non sei loggato
  else {
?> 

</p> 
<form method="post" action="login.php"> 
<div align="center"> 
<table width="118" height="116"> 
<tr> 
<td> 
<p align="center"><p align="center">Utente</td> 
<td> 
<p align="center"><p align="center"><font color="#FFFFFF"><input type="text" name="nick" size="8"></font></td> 
</tr> 
<tr> 
<td> 
<p align="center">Password</td> 
<td> 
<p align="center"><font color="#FFFFFF"><input type="password" name="psw" size="8"></font></td> 
</tr> 
<tr> 
<td> 
<p align="center"><input name="log" class="bottone" type="submit" value="Login"> 
</form> 

<td align="center"> 
<form action="registrazione.php" target="content"> 
<input name="reg" class="bottone" type="submit" value="Registrati"> 
</form></td> 
</tr> 

</div> 
</table> 


 </div> 
</body> 
</html> <?php } //chiudo else 
?>
Comunque restano magagne a livello concettuale.