New to Java

Important bits of the Main class:

Genster mechz = new Genster();

//   ...

private class ClickListener implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            if (e.getSource() == b_generate) {
                if (basic.isSelected() == true); {
                    Genster.BasicG();  // to execute what would be in that method
                    t_generate.setText(/*what to put here?*/);                    
                }

Genster class:

public class Genster {
    
    public static void BasicG() {
        String numbercool = "1337, it worked!";
        
        //return numbercool;
        
        // Without the void, NetBeans complains that I don't have a
        // return type, although I have it here, currently commented. Returning numbercool
       // would seem logical. :/
    }
    
}

So, I'm a bit stumped here. I want to set the text of a text box to what my BasicG method in Genster processes. Right now, it just assigns numbercool to something I specify. I've tried all sorts of things like mechz.numbercool and mechz.BasicG(numbercool) Help please! :D