<body>
<?[SPAN=darling][SPAN=darling]php[/SPAN][/SPAN]
if (isset($_POST['sub']))
{
$x=$_POST['x'];
$y=$_POST['y'];
$sum=$x%$y;
echo $sum;
}
?>
<form method="post">
<input type="text" name="x" /><input type="text" name="y" /><input type="submit" value="ok" name="sub"/>
</form>
</body>