<form name="monFormulaire" ...>

<select name="ad_pays" class="font" onchange="document.forms['monFormulaire'].submit();">

  <select name="ad_pays" class="font" onchange="document.forms['form01 type01'].submit();">

		<p class="double">
			<label for="f1-pays" class="oblig">* Pays :
			<span class="info"></span></label>
			<select name="ad_pays" calss="font" onchange="document.forms['form01 type01'].submit();">
			<!--<SELECT name="ad_pays" class="font">-->
			<?php
				if (empty($ad_pays))
				{
					echo '<option value="-1" selected="selected">Choisir</option>';
				}
				else
				{
					echo '<option value="-1">Choisir</option>';
				}
				// on se connecte à MySQL 
				include ('connect.php');

				$sqla = sprintf("SELECT pays_".$lg." FROM flatforswap_pays ORDER BY pays_".$lg." ASC");
				
				

				$reqa = mysql_query($sqla) or die('Erreur SQL !<br>'.$sqla.'<br>'.mysql_error());
				while($dataa = mysql_fetch_assoc($reqa))
				{
					if ($ad_pays == $dataa['pays_'.$lg.''])
					{
						echo '<OPTION value="'.$dataa['pays_'.$lg.''].'" selected="selected">'.$dataa['pays_'.$lg.''].'</option>';
					}
					if ($ad_pays != $dataa['pays_'.$lg.''])
					{
						echo '<OPTION value="'.$dataa['pays_'.$lg.''].'">'.$dataa['pays_'.$lg.''].'</option>';
					}
				}
			?>

			</select>
		</p>
		
	
		<p class="double">
			<label for="f1-ville" class="oblig">* Ville :
			<span class="info"></span></label>
			<select name="ad_ville" class="font">
			<?php
			
			// requête de jointure entre la table pays et la table ville
				
			if (!empty($ad_ville) and !empty($ad_pays) )
			{	
				
					$sqlb = sprintf("SELECT vl.ville_".$lg." FROM flatforswap_ville vl INNER JOIN flatforswap_pays py ON py.id_pay = vl.id_pay	WHERE py.pays_".$lg." = ".$ad_pays." ORDER BY vl.ville_".$lg." ASC");
					
					$reqb = mysql_query($sqlb) or die('Erreur SQL !<br>'.$sqlb.'<br>'.mysql_error());
					while($datab = mysql_fetch_assoc($reqb))
					{
						if ($ad_ville == $datab['ville_'.$lg.''])
						{
							echo '<OPTION value="'.$datab['ville_'.$lg.''].'" selected="selected">'.$datab['ville_'.$lg.''].'</option>';
						}
						if ($ad_ville != $datab['ville_'.$lg.''])
						{
							echo '<OPTION value="'.$datab['ville_'.$lg.''].'">'.$datab['ville_'.$lg.''].'</option>';
						}
					}
			}
			else
			{
				echo '<option value="-1" selected="selected">Choisir</option>';
			}
				
			?>
			

			</select>
		</p>