Question

How do I accomplish the following:
User clicks on “Start” button on an HTML page makes a GET to a getnumber.php page, that returns the number 10 in the following form: {count: 10}

Answer 1

//you jquery code
$.getJSON('getnumber.php', function(data) {
  alert(data); //returns your json_encoded number sent from getnumber.php page
});

//your php page
$arr = array("count" => 10);
echo json_encode($arr);