Async in jQuery with nested $.when

async.js

function A(){
	promises1 = new Array();
	promises2 = new Array();
	for (var i = start; i < end; i++)
	{
		B(someUri);
	}
	await();
}

function await()
{
	$.when.apply($, promises1).always(function() {
		$.when.apply($, promises2).always(function() {
			doSomethingToTheDataStoredInSomeGlobalVariableBelow();
		});
	});
}

function B(uri){
	promises1.push($.getJSON(uri, function(data){
	     someCollectionFrom_data.each(function () {
		     promises2.push($.get(someUriFrom_this, function(data){
			  extractSomeStuffFrom_data_AndStoreInSomeGlobalVariable();
             }));
	}
  ));
}