text: frames = ['content1', 'content2', 'content3', 'content4', 'content5', null];
  times = [0, // Today... 
           1000, // 
           4000, // And
           5000, // 
           7500, // this is lecture 10
           12000];
  
  document.getElementById("content").innerHTML = "\
      <div id='content1' style='display:none;position: absolute;color:white;top:25%;left:30%;margin-left:50px;font-size:440%'>Today...</div>\
  \
      <div id='content2' style='display:none;position: absolute;color:white;top:30%;left:20%;margin-left:50px;font-size:440%'>We will learn about the frame of reference...</div>\
  \
      <div id='content3' style='display:none;position: absolute;color:white;top:20%;left:10%;margin-left:50px;font-size:440%'>And...</div>\
  \
      <div id='content4' style='display:none;position: absolute;color:white;top:35%;left:20%;margin-left:50px;font-size:440%'>We will look at quaternions!</div>\
  \
      <div id='content5' style='display:none;position: absolute;color:white;top:45%;left:40%;margin-left:50px;font-size:440%'>This is lecture 15.</div>    \
  \
  <audio id='voice'>    \
      <source src='lectures/15.mp3'>    \
    </audio>    \
  </div>   \
  \
  ";
  
  