I am a brand new user of Mathematica. Every time I save my homework for my Netmath course and then reopen it, I get a syntax error message in line 3000 or 8000 etc. The message says my files have gotten corrupted. I've read about how to try to salvage theses files, but what is causing these files to get corrupted in the first place? I must be doing something wrong, but I have no idea what. How do I avoid corrupting my files in the future? I'd appreciate any help anyone can give me. Thanks a lot.