java - JButton not displaying -

hi know why "button1" not displaying? can not seem figure out when execute program works , runs not display button. appreciated thanks.

private container c; private jpanel gridpanel; private jcombobox combo; final jlabel label = new jlabel(); private jbutton button1 = new jbutton("clear"); private jbutton button2 = new jbutton("exit");  /**  * christopher haddad - 559815x  */ public planets() {     c = getcontentpane();     gridpanel = new jpanel();     gridpanel.setlayout(new gridlayout(5, 0, 0, 0));      label.setvisible(true);      combo = new jcombobox();      combo.seteditable(false);     combo.additem("no planet selected");     combo.additem("mercury");      combo.additem("venus");      combo.additem("earth");      gridpanel.add(combo);      add(button1);     add(button2);     button1.addactionlistener(this);     button2.addactionlistener(this);      c.add(gridpanel, borderlayout.north);     settitle("planet diameter");      setsize(700, 250);     setdefaultcloseoperation(jframe.exit_on_close);     setvisible(true);      combo.addactionlistener(new actionlistener() {         public void actionperformed(actionevent event) {              jcombobox combobox = (jcombobox) event.getsource();              object select = combobox.getselecteditem();              if(select.tostring().equals("no planet selected"))                 label.settext("");             else if(select.tostring().equals("mercury"))                 label.settext("the planet mercury 3100kms in diameter");             else if(select.tostring().equals("venus"))                 label.settext("the planet venus 7500kms in diameter");             else if (select.tostring().equals("earth"))                 label.settext("the planet earth 8000kms in diameter");          }     });     getcontentpane().add(combo);     getcontentpane().add(label); }      // event handling method, implementing actionperformed method of actionlistener      public void actionperformed(actionevent e)      {          // set button label number of times has been clicked         if(e.getsource() == button1) {             label.settext(" ");         }         else if(e.getsource() == button2) {             system.exit(0);         }     }  

it difficult sure, assume adding content directly top level container, jframe

jframe uses borderlayout it's default layout manager, using

add(button1); add(button2); 

basially says, add button1 center position add button2 center position. borderlayout allow single component exist @ specific location.

try adding buttons panel first...