update doet het niet?

<?php
//verwerking.php
//Dit bestand verwerkt de invoer van formulier3.php

//Verzendknop verwerken
$_POST['invoerveld'];  

$id = $_POST['invoerveld'];   
   

include "connect.php";

$sql = "SELECT ID, memberName, emailAddress, memberIP, ex FROM  members WHERE ID = '".$id."'";

$result = mysql_query($sql);

if (!$result) {
    echo "Could not successfully run query ($sql) from DB: " . mysql_error();
    exit;
}

if (mysql_num_rows($result) == 0) {
    echo "No rows found, nothing to print so am exiting";
    exit;
}
while ($row = mysql_fetch_assoc($result))

if  ($row["ex"]=='ja')
{

$nr = $row["ID_MEMBER"];

//hier word een mail verstuurd, en werkt
      
$sql = "UPDATE members SET datum = NOW(),ex= 'nee'  WHERE ID = '" . $nr . "'"; 
// dit doet niets, en ook geen fout

echo "ok";   
     

}

else
{

echo "het antwoord is neen";

}




?> 

<?php
//verwerking.php
//Dit bestand verwerkt de invoer van formulier3.php
 
//Verzendknop verwerken
$_POST['invoerveld'];  
 
$id = $_POST['invoerveld'];   
 
 
include "connect.php";
 
$sql = "SELECT ID, memberName, emailAddress, memberIP, ex FROM  members WHERE ID = '".$id."'";
 
$result = mysql_query($sql);
 
if (!$result) {
    echo "Could not successfully run query ($sql) from DB: " . mysql_error();
    exit;
}
 
if (mysql_num_rows($result) == 0) {
    echo "No rows found, nothing to print so am exiting";
    exit;
}
while ($row = mysql_fetch_assoc($result))
 
if  ($row["ex"]=='ja')
{
 
$nr = $row["ID_MEMBER"];
 
//hier word een mail verstuurd, en werkt
 
$sql = "UPDATE members SET datum = NOW(),ex= 'nee'  WHERE ID = '" . $nr . "'"; 
// dit doet niets, en ook geen fout
 
echo "ok";   
 
 
}
 
else
{
 
echo "het antwoord is neen";
 
}
 
 
 
 
?>

$sql = "SELECT ID, memberName, emailAddress, memberIP, ex FROM  members WHERE ID = '".$id."'";

$sql = "SELECT ID, memberName, emailAddress, memberIP, ex FROM  members WHERE ID = '".$id."'";

$nr = $row["ID_MEMBER"];

$nr = $row["ID_MEMBER"];

$sql = "UPDATE members SET datum = NOW(),ex= 'nee' WHERE ID = '" . $nr; 
mysql_query($sql);

$sql = "UPDATE members SET datum = NOW(),ex= 'nee' WHERE ID = '" . $nr; 
mysql_query($sql);