js切换图片

<script type=text/javascript>
var pic_width=570; //图片宽度
var pic_height=250; //图片高度
var button_pos=4; //按扭位置 1左 2右 3上 4下
var stop_time=8000; //图片停留时间(1000为1秒钟)
var show_text=0; //是否显示文字标签 1显示 0不显示
var txtcolor="#ffffff"; //文字色
var bgcolor="#ffffff"; //背景色
var imag=new Array();
var link=new Array();
var text=new Array();
//imag[1]="images/3.jpg";
imag[1]="images/1.gif";
link[1]="/Product/ProductFC.aspx";
text[1]="首页正中四轮播";
imag[2]="images/2.jpg";
link[2]="/Product/ProuctYang.aspx";
text[2]="首页正中四轮播(2)";
imag[3]="images/3.jpg";
link[3]="/Product/productdh.aspx";
text[3]="首页正中四轮播(3)";

var swf_height=show_text==1?pic_height+20:pic_height;
var pics="", links="", texts="";
for(var i=1; i<imag.length; i++){
 pics=pics+("|"+imag[i]);
 links=links+("|"+link[i]);
 texts=texts+("|"+text[i]);
}
pics=pics.substring(1);
links=links.substring(1);
texts=texts.substring(1);
document.write('<object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cabversion=6,0,0,0" width="'+ pic_width +'" height="'+ swf_height +'">');
document.write('<param name="movie" value="images/focus.swf">');
document.write('<param name="quality" value="high"><param name="wmode" value="opaque">');
document.write('<param name="FlashVars" value="pics='+pics+'&links='+links+'&texts='+texts+'&pic_width='+pic_width+'&pic_height='+pic_height+'&show_text='+show_text+'&txtcolor='+txtcolor+'&bgcolor='+bgcolor+'&button_pos='+button_pos+'&stop_time='+stop_time+'">');
document.write('<embed src="images/focus.swf" FlashVars="pics='+pics+'&links='+links+'&texts='+texts+'&pic_width='+pic_width+'&pic_height='+pic_height+'&show_text='+show_text+'&txtcolor='+txtcolor+'&bgcolor='+bgcolor+'&button_pos='+button_pos+'&stop_time='+stop_time+'" quality="high" width="'+ pic_width +'" height="'+ swf_height +'" allowScriptAccess="sameDomain" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" />');
document.write('</object>');
  </script>