writing Chr(9) to text file

I'm trying to write Chr(9) to text file: StreamWriter sw = new StreamWriter(@"c:/mcad/audit.txt"); sw.WriteLine("col1"+Chr(9)+"col2"+Chr(10)); sw.WriteLine("col1"+Chr(9)+"col2"+Chr(10)); sw.Close(); but this gives error on compile due to Chr(9). I am using System.IO. Any advice appreciated. Thanks