title: apply toggleclass function to element which has already one class
body: <p><div class="snippet" data-lang="js" data-hide="false" data-console="true">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>$("#Mpanel").on('click', '.ulmenu li', function() {
  
    var AppointType = $(this).text();
  
    if (AppointType == "R") {
      $("#spCsCharge").text("500 Rs");
      $(this).siblings(".Sappo").toggleClass();
      $(this).toggleClass("Sappo");
    } else if (AppointType == "T") {
      $("#spCsCharge").text("1000 Rs");
      $(this).siblings(".Sappo").toggleClass();
      $(this).toggleClass("Sappo Tappo");
  
    }
  
  });</code></pre>
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.ulmenu li a {
    float: left;
    text-decoration: none;
    color: white;
    padding: 11.5px 16px;
    background-color: #808080;
    border: 1px solid #fff;
  }
  .ulmenu li.Tappo a {
    background-color: #F39090;
  }
  .ulmenu li.Sappo a {
    background-color: green;
  }
  .ulmenu li.ABappo a {
    background-color: #ccc;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"&gt;&lt;/script&gt;
  &lt;div id="Mpanel" class="menu_simple"&gt;
    &lt;ul class="ulmenu"&gt;
      &lt;li&gt;&lt;a href="#"&gt;R&lt;/a&gt;
      &lt;/li&gt;
      &lt;li class="ABappo"&gt;&lt;a href="#" style="pointer-events: none; cursor: none"&gt;X&lt;/a&gt;
      &lt;/li&gt;
      &lt;li&gt;&lt;a href="#"&gt;R&lt;/a&gt;
      &lt;/li&gt;
      &lt;li&gt;&lt;a href="#"&gt;R&lt;/a&gt;
      &lt;/li&gt;
      &lt;li class="Tappo"&gt;&lt;a href="#"&gt;T&lt;/a&gt;
      &lt;/li&gt;
      &lt;li class="Tappo"&gt;&lt;a href="#"&gt;T&lt;/a&gt;
      &lt;/li&gt;
    &lt;/ul&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>constraint is 
  <strong>Select only one at a time.</strong></p>
  
  <p>This is appointment application.
  I have problem that when i select any "R" (for-regular) li this works nice.
  But for "T"(for-tatkal) it create problem.
  After un select of selected li "T" class ".Tappo" can not applies. It is look lies just default li.</p>
  
  <p>What changes required in this code?
  I don't know .please tell me.</p>