ERROR: soundinterface - loading of "indexdata/sounds/sound0.mp3" failed

<events onloadcomplete="playbackgroundsound(indexdata/sounds/sound0.mp3,0);"/>
my xml file define the event code like up.
and my html code like down
<script type="text/javascript">
var swfPano = embedpano({ swf: '<%=Url.GetScenicSpotSwfUrl(Model.ScenicSpot.Id) + "index.swf" %>',
xml: '<%=Url.GetScenicSpotSwfUrl(Model.ScenicSpot.Id) + "index.xml" %>',
id: "realScenicPlayer",
target: "RealScenicContentDiv"
});
</script>

the html is aspx file , Stored in different folders.

when I open the page, player show this message: ERROR: soundinterface - loading of "indexdata/sounds/sound0.mp3" failed
but my other image file can load. and How can I Setting the mp3 path.
thanks!

the code:
<krpano version="1.0.8">
<events onloadcomplete="playbackgroundsound(indexdata/sounds/sound0.mp3,0);"/>
<panoview h="0" v="0" fov="90"/>
<view fisheye="0" limitview="lookat" vlookatmin="-90" vlookatmax="90" fovmin="0.01" fovmax="179" fov="90" hlookat="0" vlookat="0"/>
<preview url="indexdata/index1/preview.jpg"/>
<image type="CUBE">
<left url="indexdata/index1/3.jpg"/>
<front url="indexdata/index1/0.jpg"/>
<right url="indexdata/index1/1.jpg"/>
<back url="indexdata/index1/2.jpg"/>
<up url="indexdata/index1/4.jpg"/>
<down url="indexdata/index1/5.jpg"/>
</image>
<hotspot name="spot0" onclick="loadpano(index2.xml);" url="indexdata/graphics/spots/spot1.swf" onhover="showtext(TextInfo);" ath="330.574" atv="-5.04425"/>
</krpano>

<events onloadcomplete="playbackgroundsound(indexdata/sounds/sound0.mp3,0);"/>

When the static html the sound can play. but when I Integrated into my system, the Error is show.
Code like this:
<div class="RealScenicContent" id="RealScenicContentDiv">
<noscript>
<table width="640" height="400">
<tr valign="middle">
<td>
<center>
错误:<br>
<br>
不支持Javascript<br>
<br>
</center>
</td>
</tr>
</table>
</noscript>
</div>

<script type="text/javascript">
var swfPano = embedpano({ swf: '<%=Url.GetScenicSpotSwfUrl(Model.ScenicSpot.Id) + "index.swf" %>',
xml: '<%=Url.GetScenicSpotSwfUrl(Model.ScenicSpot.Id) + "index.xml" %>',
id: "realScenicPlayer",
target: "RealScenicContentDiv"
});
</script>