Would you mind correcting my grammar or whatever mistakes my letter has?
Dear Mrs. ......
As I mentioned in the interview, I am writing to you to request (or: I wish to request/I would like to request) three weeks' leave. I have important family matters to deal with and I need to return home for these three weeks. I hope you will understand my situation and grant me this leave.
I am aware of my entitlement leave for the period from June 2008 to March 2009.
Please find attached my Annual Leave Form Request. (or: I am attaching my Annual Leave Form Request.)
Thank you in advance for your consideration of my request.