Want to display Thai text in dynamic Classic text field in AS2.0.
Currenlty using Arial font family.
Don't want it to change it into Tahoma/Arial Unicode MS or Change to Use Device Font or migrate to AS3 for TLF text field.
Sample text for reference: กขฃคฅฆงจฉชซฌฌญฎฏฐฑฒณ
The codepage of the OS has a lot of control over what glyphs actually get embedded. If you're on a Thai operating system then you have a chance of embedding that range with Arial. Unfortunately if your OS is not then Arial does not embed multi-byte characters with basic fonts like Arial and Verdana. I really don't know why as they're fully capable of displaying these characters. If you use Flex you can get around this by embedding ranges via metadata but if you're using AS2.0 I know that's not an option.
You must choose a different font or use device fonts for Arial or Verdana to work without a Thai codepage or Flex.
Here's a couple screenshots of the embed (Flash CS5.5). Notice I have ticked off SimChi for Arial and MS UI Gothic between both shots. However notice at the bottom right how many estimated glyphs it embeds. Arial is only about a hundred, MS UI Gothic is over 8000.
MS UI Gothic:
I'm just showing an extreme example but you can clearly see the Chinese is not being embedded in Arial. Thai is much smaller (91 glyphs) but it still suffers the same issue.
These fonts in my list aren't the ones you mentioned (Tahoma/Arial Unicode, MS Sans Serif, etc) but support Thai. I didn't install them and I'm on an English OS so maybe you have them:
You can see the glyphs are added (the valid glyphs) when I tick off only Thai: