var how_many_js=6;
var now = new Date()
var sec = now.getSeconds()
var js1 = sec % how_many_js;
js1 +=1;
if (js1==1){
url="http://www.myshinglesinfo.com/include/pd1.txt";
}
if (js1==2){
url="http://www.myshinglesinfo.com/include/pd3.txt";
}
if (js1==3){
url="http://www.myshinglesinfo.com/include/pd4.txt";
}
if (js1==4){
url="http://www.myshinglesinfo.com/include/pd1.txt";
}
if (js1==5){
url="http://www.myshinglesinfo.com/include/pd3.txt";
}
if (js1==6){
url="http://www.myshinglesinfo.com/include/pd4.txt";
}

document.write("<script type='text/javascript' src='" + url +"'></script>");