You could add a keyListener instead.
phonefield.addKeyListener(new KeyAdapter() {
public void keyPressed(KeyEvent evt) {
if(evt.getKeyCode() == evt.VK_ENTER){
System.out.println("The numbers you enter are "+phoneField.getText());
}
}
});
If this isn't your problem, you should expand a little and clarify.
EDIT:
As comments and other answers pointed out, you should go for an ActionListener
instead. Reasoning can be found below.