Encoding issues writing to txt

Hi folks, having some issues with encoding some information I am getting from a scriptUI in Indesign into a dialog box. myDialogLine in the script below is taking several user inputs, including from a dropdown and some editboxes, and is trying to write the result to an existing text file. The new line is coming in in Chinese characters, even though the inputs are all English. The client's text file is slugged UTF 16. 

I will admit to not understanding a great deal about encoding. Anyone have some tips or pointers to troubleshoot this one? Thanks in advance. Here's the snippet where I'm writing to file. 

the_link.open('a');
the_link.encoding = "UTF-8";
the_link.writeln(myDialogLine);
the_link.close();