$('.trigger').click(function(){
  if (($(this).prev('.flexBoxContent').hasClass('activeone')) == false) {
    $('.trigger').html('<img src="fileadmin/img/accordeonMore.png" width="57" height="23" />');
    $(this).html('<img src="fileadmin/img/accordeonClose.png" width="57" height="23" />');
    $('.flexBoxContent').removeClass('activeone').slideUp(400);
    $(this).prev('.flexBoxContent').addClass('activeone').slideDown(400);
  } 
  else{
    $('.trigger').html('<img src="fileadmin/img/accordeonMore.png" width="57" height="23" />');
    $('.flexBoxContent').removeClass('activeone').slideUp(400);
  };
  
  
});