title: Slick2D Mouse event propagation
body: <p>I am implementing a small game ( Basic game state) and I have a hard time with the buttons navigation.
  I have a class Menu which contains 3 button: Play, How To Play and Exit.
  For example when I click How To Play button it redirects me to the How To Play class. 
  In How To Play class I have just a button: Back which is suppose to redirect me back to the Menu class. 
  Everything is working but when I click the back button it exit the game, and this is because it has the same coordinates as the Exit button from Menu.
  How can I stop the propagation?
  My code is like:</p>
  
  <pre><code>Main Class:
  
  public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException{ // update the images on screen to create image movement illusion
      Input input = gc.getInput();
      mouseX = Mouse.getX();
      mouseY = gc.getHeight()-Mouse.getY();
      position = "*xpos: "+mouseX+" ypos:"+mouseY;
      buttonsListener(input, sbg);
  }
  public void buttonsListener(Input input, StateBasedGame sbg) throws SlickException
  {
  
      if((mouseX&gt;130&amp;&amp;mouseX&lt;477)&amp;&amp;(mouseY&gt;308&amp;&amp;mouseY&lt;377))//play button
          if(input.isMouseButtonDown(0))
              sbg.enterState(1);  
  
      if((mouseX&gt;130&amp;&amp;mouseX&lt;477)&amp;&amp;(mouseY&gt;408&amp;&amp;mouseY&lt;477))//how to play button
          if(input.isMouseButtonDown(0))
              sbg.enterState(2);
  
      if((mouseX&gt;130&amp;&amp;mouseX&lt;477)&amp;&amp;(mouseY&gt;508&amp;&amp;mouseY&lt;577))//exit button
          if(input.isMouseButtonDown(0))
              System.exit(0);
  }
  </code></pre>
  
  <p>And:</p>
  
  <pre><code>HowToPlay Class: 
  
  public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException{
      Input input = gc.getInput();
      mouseX = Mouse.getX();
      mouseY = gc.getHeight()-Mouse.getY();
  
      if((mouseX&gt;130&amp;&amp;mouseX&lt;477)&amp;&amp;(mouseY&gt;508&amp;&amp;mouseY&lt;577))//back button
          if(input.isMouseButtonDown(0))
              sbg.enterState(0);
  }
  </code></pre>
  
  <p>Please help, thanks.</p>