Fonts error when I used 2 types of fonts in 1 file

[cmengenie]

If I post this thread in wrong palce, Moderators please help me move it into right place. Thanks.

I have one file word. I typed text in Vietnamese (I come from Viet Nam). When I used character three dots (...), quotes (""), parentheses ('')... immediately it turns into square box. I have to highlight it and select the font is arial each time



How can I fix this problem? Thanks for any comments.

Regards,