title: check if the div id in JavaScript
body: <p>I have project that concerns about calendars, at first i have 1 calendar and now i want to have another one but they have different values.</p>
  
  <pre><code>&lt;div id="cal"&gt;
  ....
  &lt;/div&gt;
  &lt;div id="calq"&gt;
  ....
  &lt;/div&gt;
  </code></pre>
  
  <p>my question is, how can I check if <code>div</code> id is "calq" in javascript?</p>
  
  <p>if div.id == "calq" ?</p>
  
  <p>...
  at first i have ...</p>
  
  <pre><code>&lt;script type="text/javascript"&gt;
      monthYear = Date.today();
      var cal = new Calendar();
      cal.generateHTML();
      $('#cal').html(cal.getHTML());
      setMonthPrice();
      setSpecialPrice()
  &lt;/script&gt;
  </code></pre>
  
  <p>then i added </p>
  
  <pre><code>&lt;script type="text/javascript"&gt;
      monthYear = Date.today();
      var calq = new Calendar();
      calq.generateHTML();
      $('#calq').html(calq.getHTML());
      setMonthQuantity();
      setSpecialQuantity();
  &lt;/script&gt;
  </code></pre>
  
  <p>but the <code>setMonthQuantity()</code> also called by <code>cal</code>, i just want the <code>setMonthQuantity()</code> only for <code>calq</code></p>
  
  <pre><code>function setMonthQuantity()
  {
      var weekdayBaseQuantity;
      weekdayBaseQuantity = {{ product.quantity }};
  
      $('td.calendar-day').append('&lt;div class="dayquantity"&gt;' + weekdayBaseQuantity + '&lt;/div&gt;');
      $('td.Sat .dayquantity, td.Sun .dayquantity').text( weekdayBaseQuantity );
  }
  </code></pre>