I need help updating a database using php?

[Cazpa]

Here is what I am trying to use, can you please help me fix this problem:

$query = "UPDATE products SET(title, description, price, ukpost)
VALUES('" . $p_title . "', '" . $p_description . "', '" . $p_price . "', '" . $p_ukpost . "')";
$result = mysql_query($query);
if (!$result) {
$errormessage = mysql_error();
echo "Error with query: " . $errormessage;
exit();
}
printf ("This product has been updated in the database
- %s %s", $p_title, $p_price);
mysql_close();
}


Thanks in advance