title: Change value of CSS subclass in Javascript
body: <p>So here I have a simple class / subclass that is in a style.css.  I can't assign the element an id or define it in the CSS as an id using #.  So no easy getElementById().  I need to change the "top" value to various sizes dynamically using javascript or jquery.</p>
  
  <pre><code>.slider-edit .bx-prev {
      position: absolute;
      top: 265px;
      left: -32px;
      width: 31px;
      height: 31px;
      text-indent: -999999px;
      background: url(../images/icon_arrow_left.png) no-repeat 0 -31px;
  }
  </code></pre>
  
  <p>I've searched the site and web, trying things like this with no luck.</p>
  
  <pre><code>$("slider-edit bx-prev").css("top","100px");
  $(".slider-edit .bx-prev").css("top","100px");
  document.getElementsByClassName('slider-edit bx-prev').style.top = "100px";
  document.getElementsByClassName('.slider-edit .bx-prev').style.top = "100px";
  </code></pre>
  
  <p>Any help would be appreciated.</p>