清宫前吃的是什么药:网页制作 公告速度的设置

请问这个公告滚动速度怎么变慢点啊小弟谢谢了

<SCRIPT LANGUAGE="JavaScript">
<!-- Begin
function scrollerObj(name,initH,initW,heightB,widthB,content,initBg,Bg,speed,initFl){
this.name=name;
this.initH=initH;
this.initW=initW;
this.heightB=heightB;
this.widthB=widthB;
this.content=content;
this.initBg=initBg;
this.Bg=Bg;
this.iniFl=initFl;
this.speed=parseInt(speed);
this.timer = name + "Timer";
this.elem;
this.getElement = getElement;
this.createLayer=createLayer;
this.scrollLayer = scrollLayer;
this.scrollLoop=scrollLoop;
this.createLayer();
this.getElement();
this.scrollLayer(); }
function scrollLoop(s){ this.speed = s; }
function scrollLayer(){
if(parseInt(this.elem.style.top)>(this.elem.offsetHeight*(-1))){
this.elem.style.top = parseInt(this.elem.style.top)-this.speed; }
<!-- 此网页中的特别动态效果使用“有声有色 2004”软件编辑制作！-->
<!-- “有声有色 2004”--最好的网页特效制作编辑软件，制作特效您只需轻点几下鼠标即可完成！ -->
<!-- 软件下载地：酷博软件网 --><!-- 网站地址：http://www.coolboo.com -->
<!-- 软件作者：朱 江(Richie) --><!-- E-mail:richie@coolboo.com -->
else {this.elem.style.top = this.initH;} }
function getElement(){
if(document.getElementById){
this.elem = document.getElementById(this.name); }
else if (document.all){
this.elem = document.all[name]; }
else if (document.layers){
this.elem = document.layers[name]; } }
function createLayer(){
if(document.getElementById || document.all){
document.write('<div id="layer'+this.name+'" style="font-family:宋体; font-size:9pt; color:#000000; position:relative;overflow:hidden;float:'+this.initFl+';background-color:#'+this.initBg+';border:1px solid black;width:'+this.initW+'px;height:'+this.initH+'px;" onMouseover="'+this.name+'.scrollLoop(0)" onMouseout="'+this.name+'.scrollLoop('+this.speed+')">');
document.write('<div id="'+this.name+'" style="position:absolute;top:'+this.initH+'px;left:0px;border:0px solid black;width:'+this.widthB+'px;height:'+this.heightB+'px;background-color:#'+this.Bg+'">');
document.write(this.content);
document.write('<\/div><\/div>');}
else if(document.layers){
document.write('<ilayer name="'+this.name+'" bgcolor="#'+this.Bg+'" width="'+this.widthB+'" height="'+this.heightB+'">'+this.content+'<\/ilayer>');
return; }
if(this.scrollLayer){
this.timer = setInterval(this.name+'.scrollLayer()','30'); } }
var c = new scrollerObj('c','74','159','74','159','大撒犯得上犯得上大师傅但是发射点大师傅 ','FFCC00','FFCC00','2','center');
// End -->
</SCRIPT>