My notebook has Intel CPU, running Windows Vista. My program looks like this :

public class Tool_Lib_Simple
{
  public static void main(String[] args)
  {
    System.out.println("123");
  }
}

When I run it, I expect to see : "123", but the output was : "Hi NM : How are you NM ?" which was the old output from two days ago before I changed my program. If I copy this program into another project in Netbean 6.7, it will run correctly and output "123", and if I change the program name from "Tool_Lib_Simple" to something else, it will also output "123", but just not under the name of "Tool_Lib_Simple" in the current project's src directory, I've deleted the "build" directory and did re-compile, re-build, it still gives me "Hi NM : How are you NM ?" as a result, seems to me the old version of my program is saved in the hard drive or ram and got stuck there, I've programmed many years, hardly ever encounter this kind of problem, how to fix this ?

Frank