<?
    $IdVar = $_POST['rowId'];
    $DataVar = $_POST['NewData'];



    $server   = "localhost"; // MySQL hostname
    $username = "xxxxxx"; // MySQL username
    $password = "xxxxxx"; // MySQL password
    $dbname   = "test"; // MySQL db name

    $db = mysql_connect($server, $username, $password) or die(mysql_error());
          mysql_select_db($dbname) or die(mysql_error());


      $result = mysql_query("update testDb SET username ='$DataVar' WHERE ID = '$IdVar'");
     if (!$result) {
                 die('Invalid query: ' . mysql_error());
                }

    echo "Success";

    ?>

echo ( mysql_affected_rows() > 0 ) ? "Success update" : "No rows update";

$result = mysql_query("update testDb SET username ='$DataVar' WHERE ID = '$IdVar'");

if(mysql_errno($db)!=0) echo "Something went wrong";

$result = mysql_query("update testDb SET username ='Rolf' WHERE ID = '3'")