totalDiv = 14;
currDiv = 1;
oldDiv = 2;
function changeSay(){

for(i=0;i<totalDiv;i++)
document.getElementById("div"+(i+1) ).style.display = "none";


document.getElementById("div"+ currDiv).style.display = "block";
tm=100
for(op = 1; op<15; op++){
setTimeout('changeOpacity("div'+ currDiv + '",' + op + ')', tm);
tm=tm+200;
}

tm=7500

for(op = 14; op<=0; op--){
setTimeout('changeOpacity("div'+ currDiv + '",' + op + ')', tm);
tm=tm+100;
}

oldDiv = currDiv;
currDiv = currDiv + 1;

if(currDiv > totalDiv) currDiv = 1;
self.setTimeout('changeSay()', 3000);
}
function changeOpacity(divId,opa){

document.getElementById(divId).className = "st"+opa;

}
changeSay();