To Trai Coc Xanh:

First of all, thank you for the instructions. I'll try and let you know.

Second, You should write: First, instead of firstly

Third. You wrote, "You unwanted change language to Vietnamese from English!? Did you mean that I don't have to change language to Vietnamese? If so, then, you may want to say, "You don't want to change language to Vietnamse". OR Did you mean that I have to change the language back to English? Then, say, "Change the language back to English."
Please do not use such sentence. They don't use such sentence in books and magazines and in every day life because it is too cliche (ca?i lu*o*ng).

The following is my personal email address:

vicdangchuong@yahoo.com

If you want, you can contact me at my email. I will try my best to help you on your English.

You Have A Nice Day,

Nguyen Dang Chuong