There is this piece of ajax code:

$.ajax
({
    type: "POST",
    dataType: "text",
    url: "index.php",
    dataType: 'text'
    data: { option: option number },
    success:function(data)
    {
        alert(data);
    }
})

The 'option.number' variable generates a new number each time. In 'alert' this number is displayed successfully, but in php it doesn't.

I tried to output like this:

if(isset($_POST['option']))
{
    $option= $_POST['option'];
    echo 'Number: '.$option.'';
    exit();
}

gives a blank page. Please help, I've been racking my brains for 3 days how to display a variable from ajax in php. Thank you very much in advance!