How to create an X++ batch job in Axapta 3.0?

static void ExternalDataRead(Args _args)
{
...
}

class MyBatchJob extends RunBaseBatch
{
}

public container pack()
{
    return connull();
}

public boolean unpack(container packedClass)
{
    return true;
}

public void run()
{
    ;
    ...
    info("MyBatchJob completed");
}

static void main(Args _args)
{
    MyBatchJob myBatchJob = new MyBatchJob();
    ;
    if(myBatchJob.prompt())
    {
        myBatchJob.run();
    }
}

server client static public ClassDescription description()
{
    return "My batch job";
}