Adding 1 to a page_count field

So i need to add 1 to the INT in my “play_count” field each time this script is executed.


$sql1="UPDATE Movies SET play_count = play_count+1 WHERE id = 'id'";
$result1 = mysql_query($sql1) or die (mysql_error());

if($result1)
{
echo "YES"."<BR/>";  
}
else
{
echo "Error";
}