function jsonp(url, callback) {
var callbackName = 'jsonp_callback_' + Math.round(100000 * Math.random());
window[callbackName] = function(data) {
delete window[callbackName];
document.body.removeChild(script);
callback(data);
};
var script = document.createElement('script');
script.src = url + (url.indexOf('?') >= 0 ? '&' : '?') + 'callback=' + callbackName;
document.body.appendChild(script);
}
jsonp('http://www.helloword.com', function(data) {
alert(data);
});
