I updated an entry about "UploadDir", by courtesy of Matthew

Thanks for finding this! It's just what I've been looking for. I had hard coded a way to force uploads into certain folders, but that made upgrading difficult.
It took me a minute to realize how this worked though, so I thought I'd elaborate on your post. This text:
audio:mp3,wma,m4a,midi,wav,aiff
videos:mp4,m4v,mpeg,avi,mov,wmv
images:bmp,jpg,jpeg,gif,tif,tiff,png
text:txt
docs:pdf,doc,xls,ppt
src:pl,c,cc,pas,rb
archive:bz2,cab,gz,jar,lzh,rar,tar,taz,zip
...is a list of directories and the file types that go into them. So if you want your uploaded images to go into a directory called "my_photos", you'd just change the one line from this:
images:bmp,jpg,jpeg,gif,tif,tiff,png
to this:
my_photos:bmp,jpg,jpeg,gif,tif,tiff,png
When you select a file for uploading in the uploader dialog it will autofill the directory in the form field. Nice!

It was really helpful for me, so I replied him.

Hi, matthew,
Thank you for your email.
It's glad to hear that my journal have been useful for you!
And also thank you for your proofreading.
I think my journal is hard to read 'cause I'm pure Japanese and not
fluent in English.
Your proof reading is very useful.
May I use your document to modify my past entry?
Also, I'd like to quote your email to show my gratitude. May I that?
Anyway, thank you very much!

I happily got an email from him again.

Sure. Use what you need!
What you put up was extremely helpful! Thanks again for posting it. UploadDir was exactly what I needed, but since the support files are all in Japanese it took me some guessing to see how it worked. I hoped my comments will help someone else get it up and running.
You're English is great!

Now, I updated my old entry, so it might be more understandable than before.

I'm very happy because this email-exchange brings me three delightful things.

1. My entry could help another Movable Type users.
2. I got a proofreading and made my entry better.
3. I could interact with other Movable Type users in the world.

As I write on my toppage, I have three goals with my blog.

1. Introducing tips and how-to techniques of MT and MTOS, such as template settings and plugins.
2. Brushing up my English communication skill.
3. Interacting with all of Movable Type users in the world.

I got these things with interacting, and I was very happy that this blog was useful for someone.

I'm waiting for your feedback, proofreading, and indicating.

And, thank you for your courtesy, Matthew!