Greetings!!!

I have a problem that I haven't discover the solution and I need a help of you!...

I have a DB table with a quantity field that I update frequently. The table have some registers and I want to see the sum of that quantities of them.

My situation in this moment:


PHP Code:
PHP Code:
<?  
                    $sql = "select * from cart where session = '$sid'"; 
                      $query = query($sql); 
                    $conta = mysql_num_rows($query); 
                    for ($i=0;$i<$conta;$i++) 
                    { 
                     
                        $arrw = mysql_fetch_array($query); 
                         
                     
                ?> 
                 
                <td align="right"><h2><a href="carrinho.php" target="_blank">Carrinho</a> - tem <em><? if($arrw["quant"]) echo $arrw["quant"]; else echo "0"; ?></em> produtos</h2></td> 
             
                 
                <? } ?>
In this case appears a number of phrases as the number of registers that I have update.

Any sugestion??