<?php

//script A

session_start();

$annee=2010;

$mois=10;

$_SESSION["annee"]=$annee;

$_SESSION["mois"]=$mois;

?>

<a href="scriptB.php">B</a>

<a href="scriptC.php">C</a>

<?php

//script B

session_start();

if ( isset( $_SESSION['annee'] ) )

{

$annee=$_SESSION["annee"];

echo "an=$annee";

}

if (isset( $_SESSION['mois'])){

$mois=$_SESSION["mois"];

echo "mois=$mois";

}

$annee=2011;

$_SESSION["annee"]=$annee;

Unset($_SESSION["mois"]);

?>

<a href="scriptA.php">A</a>

<a href="scriptC.php">C</a>

<?php

session_start();

if (isset( $_SESSION['annee'] ) )

{

$annee=$_SESSION["annee"];

echo "an=$annee";

}

if (isset( $_SESSION['mois'] ) ) {

$mois=$_SESSION["mois"];

echo "mois=$mois";

}

else

echo "mois inexistant";

?>

<a href="scriptA.php">A</a>

<a href="scriptB.php">B</a>