Change content of a div at specific time

Try something like;

function messager(time){
    alert(time);
}
messager(currentTime);
setTimeout(messager(currentTime), 1000);

This function takes time as input. Also setTimeout function will call the function every 1 sec and run the code. Hope this helps.

What you want to do is set an interval to check your currentTime variable as the video plays. There are many ways to do this but here is a simple example of what you need to do.

function alertPlayerTime(){
    alert("Track is " + currentTime + " seconds in.");
    // other code can go here as well
}
setInterval(alertPlayerTime, 1000); 

Send the function as a variable into setInterval and time is in milliseconds so you can check it how ever often you want. There are numerous posts in regards to this type of solution like this one.

I have done that myself

<script type="text/javascript">
            $(document).ready(function(){
              $("#jquery_jplayer_1").jPlayer({

              timeupdate: function(event) { 
              var time = event.jPlayer.status.currentTime;
                  if (time > 2) $('#comment').html('My first comment'); 
                  if (time > 4) $('#comment').html('My second comment');
                  if (time > 8) $('#comment').html('My third comment'); 
                  if (time > 15) $('#comment').html('My 4th comment');
                  if (time > 25) $('#comment').html('My 5th comment');  
                  if (time > 35) $('#comment').html('My 6th comment');
                  if (time > 50) $('#comment').html('My 7th comment');  
                  if (time > 60) $('#comment').html('My 8th comment');
                  if (time > 70) $('#comment').html('My 9th comment');  
                  if (time > 90) $('#comment').html('My 10th comment');
                  if (time > 120) $('#comment').html('My 11th comment');    
                  if (time > 150) $('#comment').html('My 12th comment');
                  if (time > 180) $('#comment').html('My 13th comment');    
                  if (time > 200) $('#comment').html('My 14th comment');
               },

                ready: function () {
                  $(this).jPlayer("setMedia", {
                    title: "Bubble",
                    m4a: "http://www.jplayer.org/audio/m4a/Miaow-07-Bubble.m4a",
                    oga: "http://www.jplayer.org/audio/ogg/Miaow-07-Bubble.ogg"
                  });
                },
        cssSelectorAncestor: "#jp_container_1",
        swfPath: "/js",
        supplied: "mp3, oga",
        useStateClassSkin: true,
        autoBlur: false,
        smoothPlayBar: true,
        keyEnabled: true,
        remainingDuration: true,
        toggleDuration: true,
        cssSelectorAncestor: "",
        cssSelector: {
          currentTime: "#state1",
        }       
      });
    });
          </script> 

I assume currentTime is updated by the player into an element with id 'state1'. What you can do is get it content and parse it:

var myCurrentTime = Number.parseInt(document.getElementById('state1').textContent);

and then use it in your condition.

To do so periodically:

setTimeout(function(){
    var myCurrentTime = Number.parseInt(document.getElementById('state1').textContent);
    .... handling logic here
}, 1000);