dear sir/madam, personally i feel that i'm the right choice to do this work. i'm having more than 10 years of experience in this field. i'll finish the error free work on or before the stipulated time. give me this work. if you are satisfied you can continue with me. otherwise you can go for another person. but, i'm sure that i'll finish the work in the line of your expectation. this is not because of over confidence but because of self confidence.
expecting your positive result. thanking you!