if ($action="check") {
$text = array($line1, $line2);
foreach($text as $result)
if (!empty($result)) {
echo $result."
";    
} 
}

Linie 1  <input type="text" name="line1" class="button" size="40">
Linie 2  <input type="text" name="line2" class="button" size="40">

if ($action="check") {
$text = array($_POST['line1'], $_POST['line2']);
foreach($text as $result)
if (!empty($result)) {
echo $result."
";    
} 
}

if ($action = "check") 
{
    foreach($_POST as $key => $result)
    {
        if (!empty($result)) 
        {
            echo "$key: $result
";   
        }
    }
}

foreach($_POST as $key => $result)