怎么在一个HTML页面里插入一个FLASH 文件 30秒后自己消失的代码是什么？

html文件里加这段代码。
photo.js的代码：
function findObj(theObj, theDoc)
{
var p, i, foundObj;
if(!theDoc) theDoc = document;
if( (p = theObj.indexOf("?")) > 0 && parent.frames.length)
{
theDoc = parent.frames[theObj.substring(p+1)].document;
theObj = theObj.substring(0,p);
}
if(!(foundObj = theDoc[theObj]) && theDoc.all) foundObj = theDoc.all[theObj];
for (i=0; !foundObj && i < theDoc.forms.length; i++)
foundObj = theDoc.forms[i][theObj];
for(i=0; !foundObj && theDoc.layers && i < theDoc.layers.length; i++)
foundObj = findObj(theObj,theDoc.layers[i].document);
if(!foundObj && document.getElementById) foundObj = document.getElementById(theObj);

return foundObj;
}

function showHideLayers()
{
var i, visStr, obj, args = showHideLayers.arguments;
for (i=0; i<(args.length-2); i+=3)
{
if ((obj = findObj(args[i])) != null)
{
visStr = args[i+2];
if (obj.style)
{
obj = obj.style;
if(visStr == 'show') visStr = 'visible';
else if(visStr == 'hide') visStr = 'hidden';
}
obj.visibility = visStr;
}
}
}
document.write('