title: Opening another JFrame with a button?
body: <p>This is my code. When I run my program and click btnShop the current frame disposes, but the shop frame doesn't open. </p>
  
  <pre><code>btnShop.addActionListener(new ActionListener() {
  
                          @Override
                          public void actionPerformed(ActionEvent e) {
                              frame.dispose();
                              Shopframe.setVisible(true);
  
                                  }
                              });``
  </code></pre>
  
  <p>This is the error I get hen I click the button.</p>
  
  <pre><code>Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
  at MainFrame$6.actionPerformed(MainFrame.java:457)
  at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
  at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
  at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
  at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
  at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)
  at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
  at java.awt.Component.processMouseEvent(Unknown Source)
  at javax.swing.JComponent.processMouseEvent(Unknown Source)
  at java.awt.Component.processEvent(Unknown Source)
  at java.awt.Container.processEvent(Unknown Source)
  at java.awt.Component.dispatchEventImpl(Unknown Source)
  at java.awt.Container.dispatchEventImpl(Unknown Source)
  at java.awt.Component.dispatchEvent(Unknown Source)
  at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
  at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
  at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
  at java.awt.Container.dispatchEventImpl(Unknown Source)
  at java.awt.Window.dispatchEventImpl(Unknown Source)
  at java.awt.Component.dispatchEvent(Unknown Source)
  at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
  at java.awt.EventQueue.access$400(Unknown Source)
  at java.awt.EventQueue$3.run(Unknown Source)
  at java.awt.EventQueue$3.run(Unknown Source)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
  at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
  at java.awt.EventQueue$4.run(Unknown Source)
  at java.awt.EventQueue$4.run(Unknown Source)
  at java.security.AccessController.doPrivileged(Native Method)
  at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
  at java.awt.EventQueue.dispatchEvent(Unknown Source)
  at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
  at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
  at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
  at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
  at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
  at java.awt.EventDispatchThread.run(Unknown Source)
  </code></pre>
  
  <p>I have been playing around with different methods etc. for over an hour. I just can't get this to work. All I want to do is open the shop frame. Anyone have any ideas as to what I'm doing wrong here?</p>