var scrollCount=1;
var pauseTime=10*1000; /*数字越小移动的时间越快*/
var timer;
function changeClips() {
 for (i=1; i<4; i++){
  var allCtn="ctn"+i;
  var allTtl="ttl"+i;
  document.getElementById(allCtn).style.display="none";
  document.getElementById(allTtl).className="proButton";}} 

function ttlOn(n) {  
 var curCtn="ctn"+n;
 var curTtl="ttl"+n;
 changeClips();
 document.getElementById(curCtn).style.display="block";
 document.getElementById(curTtl).className="proCurrent";
 scrollCount=n;} 
function affScroll() {stopScroll();ttlOn(scrollCount);
 scrollCount+=1;
 if (scrollCount==4) {scrollCount=1;}
  timer=setTimeout("affScroll()",pauseTime);} 
function stopScroll() {clearTimeout(timer);}