prova questo esempio:

<script>
function controlla()
{
alert("CIAO");
}
</script>

<form name="form" id="form" method="post" action"#" onsubmit="controlla();">
<button name="nome" value="1">1</button>
<button name="nome" value="2">2</button>
<button name="nome" value="3">3</button>
<button name="nome" value="4">4</button>
</form>

<hr>

<?= $_POST[nome]?>