diff --git a/BuildServer/lib/tasks/conditional.js b/BuildServer/lib/tasks/conditional.js
index 9852c24..2148f2e 100644
--- a/BuildServer/lib/tasks/conditional.js
+++ b/BuildServer/lib/tasks/conditional.js
@@ -11,9 +11,7 @@ module.exports = function (params, processor) {
 				return processor.done();
 			}
 
-			processor.processTask(params.task, function () {
-				processor.done();
-			});
+			processor.processTask(params.task, processor.done.bind(processor));
 		}
 	};
 };
diff --git a/BuildServer/lib/tasks/sequential.js b/BuildServer/lib/tasks/sequential.js
new file mode 100644
index 0000000..c1b6cb0
--- /dev/null
+++ b/BuildServer/lib/tasks/sequential.js
@@ -0,0 +1,22 @@
+"use strict";
+
+var async = require("async");
+
+var series = function (tasks, callback) {
+	console.log("arguments:");
+	console.log(arguments);
+	console.log("first task:");
+	console.log(tasks[0]);
+	tasks[0]("xxx");
+	console.log("executed tasks[0]");
+	async.series(tasks, callback);
+}
+
+module.exports = function (params, processor) {
+	var mapper = Function.bind.bind(processor.processTask, processor);
+	return {
+		process: function () {
+			async.series(params.tasks.map(function (element) { return mapper(element); }), processor.done.bind(processor));
+		}
+	};
+};