var dt= new date();
dt.settime(date.gettime() + (3* 60 * 1000));
$.cookie('username', 'admin', { expires: dt});

$.removeCookie("username");
$.cookie('username',"null");

/*!
 * jQuery Cookie Plugin v1.4.1
 * https://github.com/carhartl/jquery-cookie
 *
 * Copyright 2006, 2014 Klaus Hartl
 * Released under the MIT license
 */
(function (factory) {
  if (typeof define === 'function' && define.amd) {
    // AMD (Register as an anonymous module)
    define(['jquery'], factory);
  } else if (typeof exports === 'object') {
    // Node/CommonJS
    module.exports = factory(require('jquery'));
  } else {
    // Browser globals
    factory(jQuery);
  }
}(function ($) {
  var pluses = /\+/g;
  function encode(s) {
    return config.raw "') === 0) {
      // This is a quoted cookie as according to RFC2068, unescape...
      s = s.slice(1, -1).replace(/\\"/g, '"').replace(/\\\\/g, '\\');
    }
    try {
      // Replace server-side written pluses with spaces.
      // If we can't decode the cookie, ignore it, it's unusable.
      // If we can't parse the cookie, ignore it, it's unusable.
      s = decodeURIComponent(s.replace(pluses, ' '));
      return config.json ? JSON.parse(s) : s;
    } catch(e) {}
  }
  function read(s, converter) {
    var value = config.raw ? s : parseCookieValue(s);
    return $.isFunction(converter) ? converter(value) : value;
  }
  var config = $.cookie = function (key, value, options) {
    // Write
    if (arguments.length > 1 && !$.isFunction(value)) {
      options = $.extend({}, config.defaults, options);
      if (typeof options.expires === 'number') {
        var days = options.expires, t = options.expires = new Date();
        t.setMilliseconds(t.getMilliseconds() + days * 864e+5);
      }
      return (document.cookie = [
        encode(key), '=', stringifyCookieValue(value),
        options.expires ? '; expires=' + options.expires.toUTCString() : '', // use expires attribute, max-age is not supported by IE
        options.path ? '; path=' + options.path : '',
        options.domain ? '; domain=' + options.domain : '',
        options.secure ? '; secure' : ''
      ].join(''));
    }
    // Read
    var result = key ? undefined : {},
      // To prevent the for loop in the first place assign an empty array
      // in case there are no cookies at all. Also prevents odd result when
      // calling $.cookie().
      cookies = document.cookie ? document.cookie.split('; ') : [],
      i = 0,
      l = cookies.length;
    for (; i < l; i++) {
      var parts = cookies[i].split('='),
        name = decode(parts.shift()),
        cookie = parts.join('=');
      if (key === name) {
        // If second argument (value) is a function it's a converter...
        result = read(cookie, value);
        break;
      }
      // Prevent storing a cookie that we couldn't decode.
      if (!key && (cookie = read(cookie)) !== undefined) {
        result[name] = cookie;
      }
    }
    return result;
  };
  config.defaults = {};
  $.removeCookie = function (key, options) {
    // Must not alter options, thus extending a fresh object...
    $.cookie(key, '', $.extend({}, options, { expires: -1 }));
    return !$.cookie(key);
  };
}));