标量值作为数组出错

Can some one help me with this code with a error on scalar value as an array?

$getal = $_POST['getal'];

For($teller=1; $teller<=11; $teller=$teller+1)
{
    $uitkomst[$teller]=$teller*$getal;
}

$getal = $_POST['getal'];
$uitkomst = array();
For($teller=1; $teller<=11; $teller=$teller+1)
{
  $uitkomst[$teller]=$teller*$getal;
}