Don't use layers, that's silly. Here's a more fleshed-out example:
<head>
<script>
var stop_on = new Image();
stop_on.src = "stop_on.gif";
var stop_off = new Image();
stop_off.src = "stop_off.gif";
var play_on = new Image();
play_on.src = "play_on.gif";
var play_off = new Image();
play_off.src = "play_off.gif";
var pause_on = new Image();
pause_on.src = "pause_on.gif";
var pause_off = new Image();
pause_off.src = "pause_off.gif";
function swap(img,which)
{
eval("document."+img+".src="+img+"_"+which+".src"

;
}
function stop_player()
{
swap("stop","on"

;
swap("play","off"

;
swap("pause","off"

;
Player.stop();
}
function pause_player()
{
swap("stop","off"

;
swap("play","off"

;
swap("pause","on"

;
Player.pause();
}
function play_player()
{
swap("stop","off"

;
swap("play","on"

;
swap("pause","off"

;
Player.stop();
}
</script>
</head>
<body>
<a href="javascript:stop_player()"><img src="stop_off.gif" name="stop"></a>
<a href="javascript

ause_player()"><img src="pause_off.gif" name="pause"></a>
<a href="javascript

lay_player()"><img src="play_off.gif" name="play"></a>
</body>
Sincerely,
Tom Anderson
CEO, Order amid Chaos, Inc.