Данные не возвращаются от сервера JSONP

function call(a) { 
  alert(a); 
} 
function getJSONP(url, callback) { 
    // Create a unique callback name just for this request 
    var cbnum = "cb" + getJSONP.counter++; // Increment counter each time 
    var cbname = "getJSONP." + cbnum;      // As a property of this function 
    if (url.indexOf("?") === -1)   // URL doesn't already have a query section 
        url += "?jsonp=" + cbname; // add parameter as the query section 
    else                           // Otherwise,  
        url += "&jsonp=" + cbname; // add it as a new parameter. 
 
    
    var script = document.createElement("script"); 
    getJSONP[cbnum] = function(response) { 
        try { 
            callback(response); // Handle the response data 
        } 
        finally {               // Even if callback or response threw an error 
            delete getJSONP[cbnum];                // Delete this function 
            script.parentNode.removeChild(script); // Remove script 
        } 
    }; 
 
    
    script.src = url;                  // Set script url 
    document.body.appendChild(script); // Add it to the document 
} 
 
getJSONP.counter = 0;  // A counter we use to create unique callback names 
 
 
getJSONP( "ph.php", call); 
getJSONP( "http://my/ph.php", call);

<?php 
	$seq = array("foo", "bar", "baz", "blong"); 
	$json = json_encode($seq); 
	echo $json