Используй $_POST
$act = filter_input(INPUT_POST, 'button', FILTER_DEFAULT);
echo '<form action="?' . uniqid() . '" method="post">' // uniqid() твой генератор ссылки
.'<input type="submit" name="button" value="home">'
.'<input type="submit" name="button" value="page1">'
.'<input type="submit" name="button" value="page2">'
.'</form>';
switch ($act) {
case 'page1':
echo '<p>You are on page ' . $act;
break;
case 'page2':
echo '<p>You are on page: ' . $act;
break;
default:
echo '<p>You are on page ' . $act;
break;
}
// more code
if ($act && $act== 'page1') {
echo '<p>You are on page: ' . $act;
}
if ($act && $act == 'page2') {
echo '<p>You are on page: ' . $act;
}