ps a mi lo q se me ocurre es:
Código PHP:
<?php
Session_start();
?>
<Html>
<Head><title>contar</title></head>
<Body>
<Form action=“index.php“ method=“post“>
<Input type=“submit“ name=“bingo“ value=“bingo“>
</form>
<?php
If(isset($_POST['bingo'])){
$_SESSION['contar']=$_SESSION['contar']+1;
}
echo $_SESSION['contar'];
?>
</body>
</html>