Based on http://dev.mysql.com/doc/refman/5.0/...statement.html, I think I have to store my query before I run it. How do I store and then execute it?

My code so far produces and error:
PHP Code:
$query "UPDATE plan SET curacc = case when curacc + 1 >= ddecpt 
                       then 0
                       else curacc + 1
                  end,
       curwipprice =    case when curacc + 1 >= ddecpt
                       then curwipprice + 1
                       else curwipprice
                  end
   WHERE id = 'LAMS-ZV90'"
;
   
   include 
"connect_to_mysql.php";
 echo 
$query '<br/>'
mysql_query(" . $query . ") or die(mysql_error());