var request = new XMLHttpRequest();
request.onreadystatechange = function () {
if(request.readyState == 4){
request.close();
}
};
var request = new XMLHttpRequest();
request.open("GET", "http://URLtoExternalJS");
request.send();
var myincludes = request.response.toString();
document.write(myincludes);
Firefox 拡張機能の既存の .js に javascript の外部ソースを追加するにはどうすればよいですか?