Flash交替出现的困惑!

我写的代码如下,就是不能轮回显示,请个位指导:
function rnd()
{ 
rnd.today = new Date(); 
rnd.seed = rnd.today.getTime();
rnd.seed = (rnd.seed * 9301 + 49297) % 233280;
return rnd.seed/(233280.0); 
}
function rand(number)
{ 
return Math.ceil(rnd() * number); 
}var fileName = new Array();
var i;fileName[0] = "images/507_233.swf";
fileName[1] = "images/sootvflash2.swf";
//fileName[2] = "/images/flyz244.swf";
//fileName[3] = "/images/wlwz210.swf";i = rand(fileName.length) - 1;document.write('<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0" width="503" height="230">');
document.write('<param name="movie" value="' + fileName[i] + '">');
document.write('<param name="quality" value="high">');
document.write('<param name="wmode" value="opaque">');
document.write('<embed src="images/afxc.swf" quality="high" pluginspage="http://www.macromedia.com/go/getflashplayer" type="application/x-shockwave-flash" width="503" height="230"></embed>');
document.write('</object>');