help me to correct my letter.

[manusjem]

Subject: Request the budget for training
Dear Sir,
I am writing this email to request the budget for training on the development of applications. The training will be held on 10[SUP]th[/SUP] October 2016 at the hotel and it costs around 5,000 Baht.
After I saw the details, I think this training is very useful for us. So I believe that I can apply the knowledge from this course to improve an application system that we have used in our company and make them more effective.
I hope you will consider and approve my request. Thank you.

Yours Sincerely
Mr. Manus
Email: manus@XXX.com

 

[tedmc]

Request [STRIKE]the [/STRIKE] for Budget for Training

Dear Sir,
I am writing this email to request[STRIKE] the[/STRIKE] for budget for training on the [STRIKE]development[/STRIKE] use of [STRIKE]applications[/STRIKE] computer software.
The training will be held on 10[SUP]th[/SUP] October 2016 at the hotel (which hotel?) and it costs around 5,000 Baht.
After I saw the details, I think this training is very useful for us. So I believe that I can apply the knowledge from this course to [STRIKE]improve an application system that we have used in our company and make them more effective.[/STRIKE] to improve the efficiency of our work using computer software more effectively.
I hope you will consider and approve my request. Thank you.

I don't think you are going for a course to learn to "develop applications", which is to design computer software. I believe it is to learn how to use computer software more effectively, thereby improving your efficiency of your work.