在jquery中创建和分配CSS类

//Dynamically getting the windows width
var windowwidth = $(window).width() - 50;

//dynamically assigning the windowwidth value to the class(dynamically)
$(window).load(function () {
    $('.cntnt').css('width', windowwidth + 'px');
})


$("#menu-toggle").click(function(e) {
    e.preventDefault();
    $('.wrapper-content').toggleClass('cntnt');
});

#wrapper {
    padding-left: 0;
    -webkit-transition: all 0.5s ease;
    -moz-transition: all 0.5s ease;
    -o-transition: all 0.5s ease;
    transition: all 0.5s ease;
}

#wrapper.toggled {
    padding-left: 250px;
}

#sidebar-wrapper {
    z-index: 1000;
    position: fixed;
    left: 250px;
    width: 0;
    height: 100%;
    margin-left: -250px;
    overflow-y: auto;
    background: #4a4f55;
    -webkit-transition: all 0.5s ease;
    -moz-transition: all 0.5s ease;
    -o-transition: all 0.5s ease;
    transition: all 0.5s ease;
}

#wrapper.toggled #sidebar-wrapper {
    width: 250px;
}

#page-content-wrapper {
    width: 100%;
    position: absolute;
    padding: 15px;
}

#wrapper.toggled #page-content-wrapper {
    position: absolute;
    margin-right: -250px;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>

<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" >

<div class="wrapper-content">
  <div class="container-fluid">
    <a href="#menu-toggle" class="btn pull-left" id="menu-toggle" >
      toggle menu
    </a>
    <div class="row">
      <div class="col-lg-12">
        <h1>Simple Sidebar</h1>
        <p>This template has a responsive menu toggling system. The menu will appear collapsed on smaller screens, and will appear non-collapsed on larger screens. When toggled using the button below, the menu will appear/disappear. On small screens, the page content will be pushed off canvas.</p>
        <p>Make sure to keep all page content within the <code>#page-content-wrapper</code>.</p>
      </div>
    </div>
  </div>
</div>

嗨，我正在尝试在jQuery中创建一个css类，并将其分配给jQuery中的另一个id。主要议程是，我想在jQuery中切换一个类，该类的宽度为$（window），在单击应将类切换为id的函数时，

这是我实现的代码，没有错误，但也没有输出。请帮帮我。