function slide(move) {
  var move = move;
  var el_width = 182;
  var count = $('.gallery_photos a').length;
  if (move == 'next' && $('.gallery_photos').width() < el_width * count && -1 * parseInt($('.gallery_photos').css('margin-left')) < el_width * (count - 3)) {
    $('.gallery_photos').animate({marginLeft: parseInt($('.gallery_photos').css('margin-left'))-el_width+'px'});
  }
  if (move == 'back' && parseInt($('.gallery_photos').css('margin-left')) < 0) {
    $('.gallery_photos').animate({marginLeft: parseInt($('.gallery_photos').css('margin-left'))+el_width+'px'});
  }
}

function switch_tab(id) {
  $('.tabs .tab').removeClass('tab_active');
  $('.tabs .tab[rel='+id+']').addClass('tab_active');
  $('.layers .layer').hide();
  $('.layers #'+id).fadeIn();
}

$(document).ready(function() {
  $('#tab_gallery .gallery_arrow_left').click(function() {
    slide('back');
  });
  $('#tab_gallery .gallery_arrow_right').click(function() {
    slide('next');
  });
  $('.tabs .tab').click(function() {
    switch_tab($(this).attr('rel'));
  });
});