fejl i INSERT INTO sætning. men hvor er fejlen?

$alder = $_POST["Alder"];
    $kon = $_POST["Kon"];
    $indkomst = $_POST["Indkomst"];
    $biler = $_POST["Biler"];
    $bolig = $_POST["Hus"];
    $shopping = $_POST["Onlineshopping"];
    $mail = $_POST["Email"];
    $mobiltlf = $_POST["Mobiltlf"];
    $dato = date("Y-m-d");

    include "database/database_tvguide.php";

    $sql = "INSERT INTO `konkurence_demografi` ('alder','kon','indkomst','biler','bolig','shopping','mail','mobiltlf','dato') VALUES ('". $alder ."','". $kon ."','". $indkomst ."','". $biler ."','". $bolig ."','". $shopping ."','". $mail ."','". $mobiltlf ."','". $dato ."')";
   
    mysql_query("$sql");