document.write('не найден<br><a class="audio" href="reason.mp3"></a>');

document.write('найден<br><a class="audio" href="http://jeromejaglale.com/shared/jquery_audio_player/audio/reason.mp3"></a>');

<a class="audio" href="audio/reason.mp3"> 
     Audio: An Electronic Reason 
 </a>

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img.onload = function() {
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img.onerror = function() {
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img.src = "file:///D:/big_image.jpg";
</script>

<script type="text/javascript">
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