Thread: Where is my class??

I have created a simple program to create a graphical user interface GUI window that contains the text Hello World in it, and in NetBeans it compiles and runs fine. Unfortunately, it does not run in the command prompt, although it does compile fine.
Here is my code:

//*Zachariah A Lloyd
 //* HELLO WORLD Interface*/
package guihelloworld;
import javax.swing.JOptionPane;
public class GUIHelloWorld {
    public static void main(String[] args){
        JOptionPane.showMessageDialog(null, "HELLO WORLD");}}

and as I said when I run this in NetBeans there are no errors or problems at all.
Attachment 1613Attachment 1614
However, when I try to run it in the command prompt, it won't work right, complaining about having some problem locating the main class??
Attachment 1615
I KNOW my code is correct, but it just WON'T RUN????
Can someone please tell me what this is all about?? Thanks in advance!!