about JTextField in java gui components - Box containing one line of text.

tf =	new JTextField(n);	Creates textfield n characters wide.
	s =	tf.getText();	Returns string in textfield.
		tf.setText(s);	Sets text to s.
		tf.addActionListener(lst);	Action listener lst will be called if enter typed.
		tf.setEditable(bool);	Don't allow user to edit text field used for output.
		tf.setHorizontalAlignment(align);	JTextField.LEFT (default), JTextField.CENTER, or JTextField.RIGHT