a little function to response json for ajax call

json_response.php

function json_response($data = array()) {
	// clear the old headers
    header_remove();
    // set the actual code
    http_response_code(200);
    // set the header to make sure cache is forced
    header("Cache-Control: no-transform,public,max-age=300,s-maxage=900");
    // treat this as json
    header('Content-Type: application/json');
    header('Status: 200');

    return json_encode($data);
}