function getCookie(name) {
  var dc = document.cookie;
  var prefix = name + "=";
  var begin = dc.indexOf("; " + prefix);
  if (begin == -1) {
    begin = dc.indexOf(prefix);
    if (begin != 0) return null;
  } else
    begin += 2;
  var end = document.cookie.indexOf(";", begin);
  if (end == -1)
    end = dc.length;
  return unescape(dc.substring(begin + prefix.length, end));
}

The cookie property includes all cookies that were set for a particular page. The requested cookie may or may not be the first one in the cookie property. The function first assembles the string to search in the cookie, assuming it is not the first one. The string is concatenated from a semicolon, the name of the cookie, and an equal sign. If, for example, the name of the cookie is "kuku", then the string to search is ";kuku=". If there is no match, the possibility of being the first on the cookie property is considered. If it is not found, a null value is returned:

    begin = dc.indexOf(prefix);
    if (begin != 0) return null;

  var end = document.cookie.indexOf(";", begin);
  if (end == -1)
    end = dc.length;
  return unescape(dc.substring(begin + prefix.length, end));

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