swing - java radio button, updating a JLabel -

i trying make code adds or subtracts initial value presented each time click submit. have searched multiple threads on how complete , haven't come across clear. push in right direction help.

package twopaneldesign;  import javax.swing.jframe;  import java.awt.color; import java.awt.font; import java.awt.event.actionevent; import java.awt.event.actionlistener;  import javax.swing.buttongroup; import javax.swing.jpanel; import javax.swing.jradiobutton; import javax.swing.jlabel; import javax.swing.swingconstants; import javax.swing.jbutton;  public class twopaneldesign extends jframe {      private static final long serialversionuid = 1l;      public twopaneldesign() {          getcontentpane().setlayout(null);          jpanel panel = new jpanel();         panel.setbounds(0, 0, 151, 262);         getcontentpane().add(panel);         panel.setlayout(null);          final jlabel lblyourchoice = new jlabel("your choice...");         lblyourchoice.setbounds(10, 11, 172, 14);         panel.add(lblyourchoice);          final jradiobutton rdbtnadd = new jradiobutton("add 2");         rdbtnadd.setbounds(10, 32, 109, 23);         panel.add(rdbtnadd);           final jradiobutton rdbtnminus = new jradiobutton("minus 2");         rdbtnminus.setbounds(10, 58, 109, 23);         panel.add(rdbtnminus);          buttongroup group = new buttongroup();         group.add(rdbtnadd);         group.add(rdbtnminus);          jpanel panel_1 = new jpanel();         panel_1.setbounds(97, 0, 349, 262);         getcontentpane().add(panel_1);         panel_1.setlayout(null);         panel_1.setbackground(color.blue);          final jlabel label = new jlabel("0");         label.sethorizontalalignment(swingconstants.center);         label.setbounds(67, 0, 260, 262);         label.setfont(new font("arial", font.bold + font.italic, 45));         panel_1.add(label);          jbutton btnsubmit = new jbutton("submit");         btnsubmit.setbounds(10, 88, 88, 23);         panel.add(btnsubmit);         btnsubmit.addactionlistener(new actionlistener() {             public void actionperformed(actionevent e){                 if (rdbtnadd.isselected())                     label.settext("2");                 if (rdbtnminus.isselected())                     label.settext("-2");             }         }             );        }      public static void main(string[] args) {         twopaneldesign = new twopaneldesign();         a.setsize(500,400);         a.setvisible(true);         a.setdefaultcloseoperation(exit_on_close);      } } 

you must retain previous result:

public void actionperformed(actionevent e){   int v = integer.parseint(label.gettext());   if (rdbtnadd.isselected()){     v += 2;   } else {     v -= 2;   }   label.settext(integer.tostring(v)); }