$('document').ready( function() {
  
  var animationDuration = 400;
  
  var curPageId = 'strana-1';
  
  var firstPageId = $('.section').first().attr('id');
  var lastPageId = $('.section').last().attr('id');
  
  $('#arrowLeft, #arrowRight').click(function() {
    var nextId = $('#' + curPageId).next('.section').attr('id');
    var prevId = $('#' + curPageId).prev('.section').attr('id');
    
    nextId = (nextId == undefined ? firstPageId : nextId);
    prevId = (prevId == undefined ? lastPageId : prevId);
    
    $('#arrowLeft, #arrowRight').fadeOut(150);
    
    if($(this).attr('id') == 'arrowLeft') {
      $('#' + curPageId).slideUp(animationDuration);
      $('#' + prevId).delay(animationDuration).slideDown(animationDuration);
      curPageId = prevId;
    }
    if($(this).attr('id') == 'arrowRight') {
      $('#' + curPageId).slideUp(animationDuration);
      $('#' + nextId).delay(animationDuration).slideDown(animationDuration);
      curPageId = nextId;
    }
    
    $('#arrowLeft, #arrowRight').delay(animationDuration + 200).fadeIn(150);
    
    $(this).blur();
    return false;
    
  });
  
});