Assala Mu Alaikum sir,
I am glad to say that I want to work with you. I can prove to be effective and efficient if I am awarded with the task and guided well. I have written a lot as a freelancer and hence, do have the capability to please my clients. I can also ensure that I can work with little or no supervision and thus, you would not need to worry much about me after assigning me the task.
I would be eagerly looking forward for your reply.
Thanks in advance.