[ruslan_mart]

if (isset($_POST["name"]))
{
$_SESSION['name'] = $_POST["name"];
}

if (isset($_POST["mobile"]))
{
$_SESSION['mobile'] = $_POST["mobile"];
}
if (isset($_POST["orderlist"]))
{
$_SESSION['orderlist'] = $_POST["orderlist"];

}

if (isset($_POST["city"]))
{
$_SESSION['city'] = $_POST["city"];
}

if (isset($_POST["street"]))
{
$_SESSION['street'] = $_POST["street"];
}

if (isset($_POST["adress"]))
{
$_SESSION['adress'] = $_POST["adress"];
}

if (isset($_POST["zip"]))
{
$_SESSION['zip'] = $_POST["zip"];

}
if (isset($_POST["state"]))
{
$_SESSION['state'] = $_POST["state"];

}

А не проще?

$_SESSION = $_POST;