ColdFusion with JavaScript timer

Hello~

I have am using a JavaScript timer on a .cfm page. So far everything is working, but what I want to happen is, when the time reaches zero, a button appears on the page. Right now, the timer works, but when it gets to zero, nothing happens at that point. This entire .cfm page is being used as an include on another .cfm page. I am not very familiar with Javascript, so I would appreciate any suggestions. Thanks!

<cfoutput>

    <cfset totalSeconds = #currentTopicTime#>
   
    <cfset totalMinutes = Int(#totalSeconds#/60)>
    <cfset remainingSeconds = #totalSeconds# MOD 60>

    <script type="text/javascript">
        var minutes = #totalMinutes#;
        var seconds = #remainingSeconds#;
       
        function countDown() {
          // decrease
          seconds--;
          if (seconds == -01) {
            seconds = 59;
            minutes = minutes - 1;
          } else {
           minutes = minutes;
          }
        if (seconds<=9) { seconds = "0" + seconds; }
          time = "You are required to view this page for #totalMinutes# minutes<cfif remainingSeconds NEQ 0> and <cfif remainingSeconds LTE 9>0</cfif>#remainingSeconds# seconds</cfif>.<br />You have " + (minutes<=9 ? "0" + minutes : minutes) + " minutes and " + seconds + " seconds remaining.<br />Please review this page until the timer has reached 0.<br />Please DO NOT refresh this page&mdash;this will restart the timer!";
        if (document.getElementById) { document.getElementById('theTime').innerHTML = time; }
          SD=window.setTimeout("countDown();", 1000);
        if (minutes == '00' && seconds == '00') { seconds = "00"; window.clearTimeout(SD);}
        }
       
        function addLoadEvent(func) {
          var oldonload = window.onload;
          if (typeof window.onload != 'function') {
            window.onload = func;
          } else {
            window.onload = function() {
              if (oldonload) {
                oldonload();
              }
              func();
            }
          }
        }
       
        addLoadEvent(function() {
          countDown();
        });
    </script>
   
    <hr style="margin-bottom:3px; margin-top:3px; width:90%;" />
    <p id="theTime" class="timeClass"></p>
   
</cfoutput>