$(document).ready(function() {
  $("ul#nav li").click(function() {
    $(this).siblings('li').find('ul.sub').hide();
    $(this).children('ul.sub').toggle();
	});

  var container = $('#containing_table');
  var textSizeCookieValue = readCookie('textsize');
  
  if(textSizeCookieValue) {
    container.css({ fontSize: textSizeCookieValue + 'px' });
  } else {
    createCookie('textsize', '16px', 14);
    textSizeCookieValue = '16px';
  }

  $('#increase_font_size').click(function() {
    changetextsize(1);
  });
  $('#decrease_font_size').click(function() {  
    changetextsize(0);
  });
});


function changetextsize(up) {
  var container = $('#containing_table');
  var textsize = parseFloat(container.css('font-size'));
  eraseCookie('textsize');
  if(up) {
    textsize = parseFloat(textsize) + 2;
    createCookie('textsize', textsize, 14);
  } else{
    textsize = parseFloat(textsize) - 2;
    createCookie('textsize', textsize, 14);
  }
  container.css({ fontSize: textsize + 'px' });
}

function createCookie(name, value, days) {
  if (days) {
    var date = new Date();
    date.setTime(date.getTime() + (days*24*60*60*1000));
    var expires = '; expires=' + date.toGMTString();
  }
  else var expires = '';
  document.cookie = name + '=' + value + expires + '; path=/';
}

function readCookie(name) {
  var nameEQ = name + "=";
  var ca = document.cookie.split(';');
  for(var i=0;i < ca.length;i++) {
    var c = ca[i];
    while (c.charAt(0)==' ') c = c.substring(1,c.length);
    if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
  }
  return null;
}

function eraseCookie(name) {
  createCookie(name, '', -1);
}