Any way to install Flash Player 10 on Adobe Flash CS3?

Hello!

CS3 is 12 years old. But it's what I have. The thing is that I need to export a String to a text file with FileReference like this:

var mytext: String;

mytext = "abc";

file.save(mytext, "data.txt");

And I get an error. I checked the internet and I need to change my compiler version to 10. But the thing is that in my list, it stops at Flash Player 9. Is there any way I can install the 10th version for the compiler? I really need to get this done.