php如何将if语句附加到按钮？

if($game_set->issue_challenge()){echo \"test\";}else {\"test failed\";}

<input type=\"submit\" name=\"submit\" id=\"submit\" value=\"Submit\" />

if the button isset, then $values = $_POST[\'gamelist\'] and if($game_set->issue_challenge()){echo \"test\";}else {\"test failed\";}

if (isset($_POST[\'Submit\'])) {
$values = $_POST[\'gamelist\']
if($game_set->issue_challenge()){echo \"test\";}else {\"test failed\";}
}

if ($_SERVER[\'REQUEST_METHOD\'] == \'POST\') {
    if (isset($_POST[\'submit\']) && ($_POST[\'submit\'] == \'Submit\')) {
       ... it was clicked
    }
}