Problème page blanche... Erreur PHP

<?php
if(isset($_POST['co']))
{
mysql_connect('localhost','***','***');
mysql_select_db('db20886');
$mail = mysql_real_escape_string($_POST['mail']);
$ip = mysql_real_escape_string($_POST['ip']);
$heure = mysql_real_escape_string($_POST['heure']);
$date = mysql_real_escape_string($_POST['date']);
$sql = ("SELECT * FROM pass WHERE mail='$mail' && ip='$ip'"); 
$req = mysql_query($sql) or die('Erreur SQL ! Avez vous fait l installation ?
'.$sql.'
'.mysql_error()); 
while($data = mysql_fetch_array($req)) 
{ 
$one = '1';
}else echo"Un champs est incorrect !";

$sql = ("SELECT * FROM pass WHERE date='$date' && heure='$heure'"); 
$req = mysql_query($sql) or die('Erreur SQL ! Avez vous fait l installation ?
'.$sql.'
'.mysql_error()); 
while($data = mysql_fetch_array($req)) 
{ 
$two = '1';
}else echo"Un champs est incorrect !";

if (($one&&$two) == '1') {
$sql = ("SELECT * FROM pass"); 
$req = mysql_query($sql) or die('Erreur SQL ! Avez vous fait l installation ?
'.$sql.'
'.mysql_error()); 
while($data = mysql_fetch_array($req)) 
{ 
echo $data['pass'];
}
}
}else{
mysql_close();
?>