Can anybody help me with this letter?

Can anybody help me with brushing up my letter?
I thank you in anticipation.

Dear Sir / Madam,

Some time ago I have seen the advertisement in wich you offer the possibility of taking part in a course.I read the advertisement in ‘The Times’ of 17 February.
I would be most grateful if you could send me the brochure.

I am a Dutch girl aged sixteen. I am in my final year at the higher general education. I hope to go in for a career in tourism and the hotel industry. I reason why I am applying for this post is that I want to improve my English and I think it is a good preparation ofr my future studies.
Is it possible for me to follow the course, because I am Dutch?

I look forward to hearing from you soon.

Yours faithfully,