Can anyone help make my scripts IE friendly? (JavaScript)

[Datacide]

I have a few related custom scripts I've written that work perfectly in Firefox and Chrome. I need to try and get them working in IE as well. Any insight what I need to change and why would be greaetly appreciated. This is the first script:

<script type="text/javascript">

  function getJs(src, callback) {
    if (src && typeof src === "string") {
      var el = document.createElement("script");
      el.type = "text/javascript";
      el.src = src;
      document.head.appendChild(el);
      el.onload = function(e) {
        (callback && callback instanceof Function) ? callback(e) : void(0);
      }
    }
  }

  function DelayExecute() {
    setTimeout( function(){addVideoRows()}, 2000 );
  }

  ScriptURL = "http://www.upmygame2.com/getAthleteVideos.do?athleteId="+ProfileID+"&alias=demo";

  getJs(ScriptURL); DelayExecute();

  function addVideoRows() {
    var ListHTML="";
    for (var i = 0; i < umgVideos.length; i++) {
      ListHTML += "<p><b>"+umgVideos[i].uploadDate + " &#8212 <a href='/player?videoid=" + umgVideos[i].id +"'>" + umgVideos[i].title + "<\/a><\/b><br><i>Assigned to: " + DirArray[umgVideos[i].extCoachId][0] + "<\/i><\/p>";
    }
    if (ListHTML == ""){ListHTML="No videos found.";}
    document.getElementById("VideoList").innerHTML = ListHTML;
  }

  </script>

<div id="VideoList">Looking for uploaded videos, please wait...</div>

[Lightning]

You could debug the scripts, in IE using F12. Then you can see where the problem is and you can google that or ask here again.