title: Back button pressed
body: <p>I have multiple activities with 5 different screens.How should i handle a situation if a back key is pressed ??in First Screen and other screens ?? finish() and System.exit() is not working ..What should i do to exit my application if the Back button is pressed ?? 
  The below coding does not work ?Please suggest me a way to exit an application having multiple screens</p>
  
  <pre><code> public boolean onKeyDown(int keyCode, KeyEvent event) 
   {
      if (keyCode == KeyEvent.KEYCODE_BACK) 
       {
          AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
                  this);
  
          new AlertDialog.Builder(this) .setMessage("Are you sure you want to exit?")
             .setCancelable(true)
            .setPositiveButton("Yes", new DialogInterface.OnClickListener() 
             { 
               public void onClick(DialogInterface hi, int dd) 
               {
  
                  Intent exitIntent = new Intent(Mapper.this,SplashActivity.class);
                  exitIntent.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP|Intent.FLAG_ACTIVITY_CLEAR_TOP);
                  SplashActivity.mHandler.sendEmptyMessage(0);                   
                  startActivity(exitIntent);    
  
  
               }
             }
            )
           .setNegativeButton("Cancel", new DialogInterface.OnClickListener() 
           { 
             public void onClick(DialogInterface hi, int dd) 
             {
  
             }
           }
           );
          AlertDialog alertDialog = alertDialogBuilder.create();
  
              // show it
              alertDialog.show();
        //AlertDialog alert1 = alt_bld.create();
        //alert1.setTitle("EXIT");
        //alert1.show(); 
         return true; 
       }
       return super.onKeyDown(keyCode, event);
   }
  
    And in Start.Class:
    public boolean onKeyDown(int keyCode, KeyEvent event) 
  {
      if (keyCode == KeyEvent.KEYCODE_BACK || keyCode == KeyEvent.KEYCODE_HOME) 
      {
          mHandler.removeCallbacksAndMessages(null);
          SplashActivity.this.finish();
      }
  
      return super.onKeyDown(keyCode, event); 
  }
  </code></pre>