[php] update mysql database

hello
can anyone explain me what can be wrong in this code or give me some extra lines of code to find what can wrong to this thing don’t work?

 
<?php
$dbhost = "localhost"; 
$dbuser = "xxxx"; 
$dbpwd = "xxxx"; 
$dbname = "comuna"; // change this to your database name 
$connection = mysql_connect($dbhost, $dbuser, $dbpwd); 
mysql_select_db("$dbname",$connection);
 
$id = "4";
$sala = "5";
$titulo = "5";
$info = "5";
$descriccao = 5;
 
mysql_query("UPDATE emcena SET sala='$sala', titulo='$titulo', info='$info' descricao='$descriccao', WHERE id='$id' ");
echo "File " . $id . " " . $sala . " " . $info . " " . $descriccao . " " . $titulo . " uploaded successfuly.";
//header("Location: cena.php");
?>

if i write this in a file and open in my server… it should add the data to database right? or i need any submit button or something like that? this is probably stupid but ok… i just want to understand why i can’t update the data in this table, cause i can in the other table in the same database… help me please :confused: