function musicController(){
   if(!document.getElementById('mute_music_img')){
	  document.getElementById('music').style.display = 'inline';
	  document.getElementById('play_music_img').src = 'img/sound.png';
	  document.getElementById('play_music_text').innerHTML = 'Musik ausschalten';
	  document.getElementById('play_music_text').title = 'Musik ausschalten';
	  document.getElementById('play_music_text').id = 'mute_music_text';
	  document.getElementById('play_music_img').id = 'mute_music_img';
   }else{
      document.getElementById('music').style.display = 'none';
	  document.getElementById('mute_music_img').src = 'img/sound_mute.png';
	  document.getElementById('mute_music_text').innerHTML = 'Musik einschalten';
	  document.getElementById('mute_music_text').title = 'Musik einschalten';
	  document.getElementById('mute_music_text').id = 'play_music_text';
	  document.getElementById('mute_music_img').id = 'play_music_img';
   }
}