Problem avec Formulair (formail) ()mail

Bonjour,
je vien de cree cet formulaire me je se peu pk sa marche pa svp aide moi a determine le bug

*****************fichier php*********************

<?php

if(isset($_POST)isset(['$nom']) && isset($_POST['$email']) && isset($_POST['$Tel']) && isset($_POST['$Prenom']) && isset($_POST['$Vehicule']) && isset($_POST['NBJour'])){
extract($_POST);
if(!empty($nom) && !empty($email) && !empty($Tel) && !empty($Prenom) && !empty($Vehicule) && !empty(NBJour)){
$message=str_replace("\'","'",$message);
$destinataire="chlibta@hotmail.com";
$sujet="Formulaire de contact";
$message="Une nouvelle question est arrivée \n
Civilite: $_POST['Civilite'] \n
Nom : $nom \n
Prenom : $Prenom \n
Societe: $_POST['Societe'] \n
Email: $email \n
Tel: $Tel \n
Vehicule: $Vehicule \n
Prestige: $_POST['prestige'] \n
Disopse: $NBjour";
$entete="From: $nom \n Reply-To: $email";
mail($destinataire,$sujet,$message,$entete);
echo "Le mail a bien été envoyé.";
}
else{
echo "Vous n'avez pas rempli tous les champs.";
}
}
?>

*****************************************

************fichier html*********************

<form name="reservation" method="post" action="envoyer.php">
<table width="100%" border="0" cellspacing="0">

<tr>
<td><br>
<select name="Vehicule" size="1" id="Vehicule">
<option selected>Mercedes Class S 600/500</option>
<option>Mercedes Class S 350</option>
<option >Mercedes Classe E</option>
<option>BMW Serie 7</option>
<option >Audi A8</option>
<option>Peugeot 607</option>
<option>Range Rover Sport</option>
<option>Porsche Cayenne S</option>
<option>Van De Luxe</option>
<option>Prestige*</option>
</select>
</td>
<td> <span class="Texte"> <br/>Mise à disposition de</span>
<input name="NbJours" type="text" id="NbJours" size="4">
<span class="Texte">jour(s)</span></td>

</tr>

</table>

</td>
</tr>
<tr>
<td valign="top">
<br>

<br>
<table width="100%" border="0" cellspacing="0">

<!--DWLayoutTable-->

<tr>
<td width="106" class="Texte">Civilité</td>
<td width="*" class="Texte">Mr
<input type="radio" name="Civilite" value="Mr">

Mme
<input type="radio" name="Civilite" value="Mme">
</td>
</tr>
<tr>
<td class="Texte">Nom</td>
<td><input name="Nom " type="text" id="Nom " size="64"></td>

</tr>
<tr>
<td class="Texte">Prénom</td>
<td><input name="Prenom" type="text" id="Prenom" size="64"></td>
</tr>
<tr>
<td class="Texte">Société</td>

<td><input name="Societe" type="text" id="Societe" size="64"></td>
</tr>
<tr>
<td><span class="Texte">E-mail</span></td>
<td><input name="email" type="text" id="email" size="64"></td>
</tr>
<tr>
<td class="Texte">Telephone</td>

<td><input name="Tel" type="text" id="Tel" size="64"></td>
</tr>
<tr>
<td class="Texte">prestige*</td>

<td><input name="prestige" type="text" id="prestige" size="64"></td>
</tr>

</table>
<br>
<table width="100%" border="0" cellspacing="0">

<tr>
<td>
<div align="center">
<input type="submit" name="Submit" value="Envoyer">
</div>
</td>
</tr>
</table>
</form>

******************************************************************