if(isset($_POST['yech'])){
$a = $_POST['son1'];
$b = $_POST['son2'];
$type = $_POST['type'];
if ($type == 'plus') {
$c = $a + $b;
}elseif ($type == 'minus') {
$c = $a - $b;
} elseif ($type == 'multi') {
$c = $a * $b;
}elseif ($type == 'drop'){
$c = $a / $b;
}
echo'<h2>Natija: '.$c.