Related drop-down menu

[patlap]

I have a webpage who's taking data from a mysql DB

For now on I will have only two dynamic input form object.

A drop down-menu that look through the city available.
And a second drop-down menu that show the dates available.

My db is quite short ;

 $Ville = $row['Ville'];
         $Date1 = $row['Date1'];
         $Date2 = $row['Date2'];
         $Derniermodif = $row['Derniermodif'];
         $DocId = $row['DocId']; 

For now on the city appear alright.

<tr>
<td width="290"><select name="Ville">Lieu de la formation: <?php while ($choixVille = mysql_fetch_assoc($resultat)) {
                                echo "<OPTION VALUE '" .$DocId["DocId"]."'>".$choixVille["Ville"];
                                }
                                ?></select></td>

But I'm not shure how to get the related Date 1 and 2 for the second drop-down.

Each city have 2 date available.

[Dan Grossman]

$sql = "SELECT Date1, Date2 FROM table WHERE DocId = " . $_POST['DocId']; 

[Borje]

$sql = "SELECT Date1, Date2 FROM table WHERE DocId = " . $_POST['DocId']; 

Shouldn't that be:

$sql = "SELECT Date1, Date2 FROM table WHERE DocId = " . $_POST['Ville']; 

?