title: Why javascript function is not working although there are no errors?
body: <p>here is the code:</p>
  
  <pre><code>&lt;div id="one"&gt;
  &lt;div class="options-parameters-input"&gt;
  This is testing
  &lt;/div&gt;
  &lt;/div&gt;
  &lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;&lt;br /&gt;
  &lt;table width="750" border="1" cellspacing="3" style="float:left;"&gt;
    &lt;tr&gt;
      &lt;td&gt;Type font size&lt;/td&gt;
      &lt;td&gt;&lt;textarea id="heretype"&gt;&lt;/textarea&gt;&lt;/td&gt;
    &lt;/tr&gt;
  &lt;/table&gt;
  
  $("#heretype").on("keyup",both);
  
  function both(){
  $(".options-parameters-input").css("fontSize", this.value + "px");
  }
  </code></pre>
  
  <p>link to jsfiddle</p>
  
  <p><a href="http://jsfiddle.net/gxTuG/106/" rel="nofollow noreferrer">http://jsfiddle.net/gxTuG/106/</a></p>
  
  <p>So this code works in jsfiddle as you can see, but when i transfer this code to my phpBB theme, then for some unknown reason it does not work... and in Firefox Developer Tools there is no error.. So i dont know why is not working ? what could be a problem.</p>
  
  <p>also</p>
  
  <p>if i try to use <code>$("#heretype").addEventListener("keyup",both);</code>instead <code>.on</code>
  then i receive error: </p>
  
  <blockquote>
    <p>TypeError: $(...).addEventListener is not a function</p>
  </blockquote>
  
  <p>All javascript functions including this are stored in .js file called from footer.</p>
  
  <p>also i have added <code>console.log($('#heretype').length);</code></p>
  
  <p>after that it just shows number 1 in console</p>
  
  <p>please can you help me</p>
  
  <p>Thank you</p>