Dear Professor Frank Jason,

Dear Professor Frank Jason,
I am Wang Hai ,the chairman of the student Union of our school .I am writing to invite you to give a lecture to the students in our school on what to improve the English writing from 22nd to 25th ,September ,2011.
English writing have always been our headche and we're trying every means improve it but have little good result .It would be our great honored if you could come to give us a lecture on it .Enclosing in this letter is a time schedule for it .The school would cover the traveling and other expense.
Please let me knowing your date of arrival if you can come .Unless you have any questions,please don't hesitate to contact me .Look forward to your favorably replay.
Yours.
Wang Hai.