Thai words in template

Hi. I’m a newbie for Modx.
Now, I’m designing a new template for my website, which use Thai for its content.
My template has Thai words which are transfered to "???" when I put the code in template editor.

I’ve tried to change the encoding, but it is no use.
Now, I use "UTF-8" for my encoding.

Any help please, Thank you.

update::
I also write Thai in my content.
When I firstly submit, it’s showing the right content. But, when I edited it in the manager, the Thai letters were transfered to be unread.
And the edited content will be unread.

Which version of modx are you using ?

I am fairly certain you have a mismatch between your database charset and collation. Do you know what they are actually set to in your DB when you set it up?

i’ve found a solution in
Quick Editor is OK while BackEnd editing returns scrambled chars
I export my DB and set CHARSET to utf8 and COLLATION to utf8_unicode_ci.
Then I import back to the server and add the code as stated in the solution

It solve my stated problem.
However, I’ve found another one with commenting in blog with Thai character.

By the way, I use version 0.9.6.2