$_POST[]获取不到数值啊,为什么???

Question

echo <<<'FORM'

<form action="" method="post">

<input type="number" name = "rows">行

<br/>

<input type="number" name = "cols">列

<input type="submit" value="提交";

</form>

FORM;

$rows = isset($_POST['rows']) ? $_POST['rows'] : 3;

$cols = isset($_POST['cols']) ? $_POST['cols'] : 3;

// $rows = $_POST['rows'];

// $cols = $_POST['cols'];

echo '<table border="1" cellspacing="0" cellpadding="5">';

$i = 0;

while ($i<$rows) {

echo '<tr>';

$j = 0;

while ($j<$cols) {

echo '<td>'.($i * $cols + $j).'</td>';

$j++;

}

echo '</tr>';

$i++;

}

echo '</table>';

代码如上,获取不到行和列的数值