How to write to csv file using C#?

Question

Hello, folks!

I have a problem, I have to do some measurements, and I'd like to write all results to one *.csv file... 

StreamWriter fileWriter = new StreamWriter("results.csv");

            fileWriter.WriteLine("BLA BLA");

            fileWriter.Close();

How can I just add lines to files, and do not rewrite old data?

Thx a lot.

Mei.