JavaScript that controls the player does not work

Question

Hello everyone
I have a page with an embedded video on Windows media player, and developed a javascript to control the video.
The parties that control the play, stop, pause, volume, and fast reverse fast forward work very well, but when I put a function that advances the video marks the next and previous does not work in Safari only works in Firefox and the worst and does not accuse me errors simply does not work, then I do not know what to do if someone can help me would greatly appreciate it
The codes are below
Code for embedded player
<div id="Dvideo"  style="position:absolute; width:400px; height:266px; z-index:3; visibility:hidden; left: 14px; top: 85px;">
                <object 
          id="contentPlayer"
          name="contentPlayer"
          width="400"
          height="266"
          type="application/x-ms-wmp">
                          <param name="AnimationAtStart" value="0" />
                          <param name="AutoStart" value="0" />
                          <param name="CurrentMarker" value="0" />
                          <param name="EnablePositionControls" value="true" />
                          <param name="EnableTracker" value="0" />
                          <param name="ShowAudioControls" value="0" />
                          <param name="ShowCaptioning" value="0" />
                          <param name="ShowControls" value="1" />
                          <param name="ShowDisplay" value="0" />
                          <param name="ShowGotoBar" value="0" />
                          <param name="ShowPositionControls" value="0" />
                          <param name="ShowStatusBar" value="0" />
                          <param name="ShowTracker" value="0" />
                          <PARAM NAME="EnableContextMenu" VALUE="false">
                          <param name="AllowChangeDisplaySize" value="true" />
                          <PARAM NAME="CurrentPosition" VALUE="false">
                          <param name="SRC" value="video.wmv" />
                          <param name="TransparentAtStart" value="1" />
                          <param name="uiMode" value="none"/>
                          <embed
          src="video.wmv"
          width="400"
          height="266"
          autostart="0"
          type="application/x-ms-wmp"
          id="contentPlayer"
          name="contentPlayer"
          showdisplay="0"
          showcontrols="1"
          animationatstart="0"
          transparentatstart="1"
          showstatusbar="0"
          showtracker="0"
          currentmarker="0"
        CurrentPosition="0"
          enablepositioncontrols="true"
          enabletracker="0"
          showcaptioning="0"
          showaudiocontrols="0"
          showgotobar="0"
        EnableContextMenu="false"
        AllowChangeDisplaySize="true"
          uiMode="none"
          showpositioncontrols="0"></embed>
                        </object>
javascript code
    function play()
                    var player=document.getElementById('contentPlayer');
                         document.getElementById('DInfo').style.visibility = 'hidden'
                    document.getElementById('Dvideo').style.visibility = 'visible'
                    player.controls.play();
    function pause()
                    var player=document.getElementById('contentPlayer');
                  player.controls.pause();
    function stop()
                    var player=document.getElementById('contentPlayer');
                  document.getElementById('DInfo').style.visibility = 'visible'
                    document.getElementById('Dvideo').style.visibility = 'hidden'
                    player.controls.stop();
function Volume()
          document.getElementById('contentPlayer').settings.volume  = document.getElementById('contentPlayer').settings.volume + 30 ;
function VolumeDown()
          document.getElementById('contentPlayer').settings.volume  = document.getElementById('contentPlayer').settings.volume - 30 ;
function mute() {
          var player = document.getElementById('contentPlayer');
          var mutebutton = document.getElementById('bt4');
          if (player.settings.mute) {
          player.settings.mute = false;
          return player.settings.volume + "%";
          mutebutton.src ="../images/mute_false.gif";
          } else {
          player.settings.mute = true;
          return "mute";
          mutebutton.src ="../images/mute_true.gif";
function fastforward()
          var player=document.getElementById('contentPlayer');
          player.controls.fastForward();
function fastreverse()
          var player = document.getElementById('contentPlayer');
          player.controls.fastReverse();
function GoNextMarker (mymark)
          var player = document.getElementById('contentPlayer');
          var mymark = player.controls.currentMarker + 1
          player.controls.currentMarker = mymark;
function GoPreviusMarker (mymark)
          var player = document.getElementById('contentPlayer');
          var mymark = player.controls.CurrentMarker - 1
          player.controls.currentMarker = mymark;
</div>

Answer 1

This has been discussed over and over and over and over and over and over and over and over again.
Do a forum search (right side of this page) and you will find countless posts on this.