I have a button that plays an audio file on its click listener. If the button is clicked again and again while the audio file is being played then the app crashes. What's the solution?

Here is some code for reference:

 private OnClickListener btnMercyListener = new OnClickListener()
    {

        public void onClick(View v)
        {                        
           // Toast.makeText(getBaseContext(), 
             //       "Mercy audio file is being played", 
               //       Toast.LENGTH_LONG).show();

            if (status==true)
            {
                mp.stop();
                mp.release();
                status = false;

            } 
            else
            {
            mp = MediaPlayer.create(iMEvil.this,R.raw.mercy); 


          //mp.start();

            try{
                mp.start();
                status= true; 
                //mp.release();
               }catch(NullPointerException e)
               {
                   Log.v("MP error",e.toString());
               }

            }

            mp.setOnCompletionListener(new OnCompletionListener(){ 

                   // @Override 
                   public void onCompletion(MediaPlayer arg0) { 
                      mp.release();
                      status = false;

                   } 
              }

          ); 



        }
    };