Code PHP :
<?php
$_SESSION['pseudo']=$_POST['pseudo'];
$pseudo=$_SESSION['pseudo'];
mysql_connect("xxx","xxx","xxx");
mysql_select_db("i4418016");
$retour= mysql_query("SELECT COUNT (*) AS nbre_entrees FROM Membres WHERE Pseudo= '$pseudo'") or die (mysql_error());
$donnees = mysql_fetch_array($retour);
if ($retour['nbre_entrees']==1)
{
echo "Bonjour $pseudo";
}
elseif($retour ['nbre_entrees']==0)
{
echo "Ces identifiants sont incorrects";
}
?>