How can I start a for-loop with 01 instead of 1?
for ($i = 01; $i <= 12; $i++) {
    echo "<option value='$i'";
    if ($i == $post_response[expiremm]) {
        echo " selected='selected'";
    }
    $month_text = date("F", mktime(0, 0, 0, $i+1, 0, 0, 0));
    echo ">$month_text</option>";
}

$value = $i;
if ($i < 10) {
    $value = str_pad($i, 2, "0", STR_PAD_LEFT);
}

printf("<option value='%02d'", $i);

$value = strlen($i);
            if($value==1){
                $k = "0".$i;
            }else
            {
                $k=$i;
            }
            echo "<option value='$k'";
            if ($i == $post_response[expiremm]) {
                echo " selected='selected'";
            }
            $month_text = date("F", mktime(0, 0, 0, $i + 1, 0, 0, 0));
            echo ">$month_text</option>";
        }