js跟随滚动条滚动浮动代码

var str="客服"; 
var objFT=new FloatT("FloatMenu1",str,942,137,125,200,80,10); 
objFT.FloatRun(); 
//js跟随滚动条滚动 浮动 
//pObjName:html 元素ID 
//pText:html 元素内容 
//其它自己看 
function FloatT(pObjName,pText,pstmnLEFT,pstmnGAP1,pstmnGAP2,pstmnBASE,pstmnActivateSpeed,pstmnScrollSpeed) 
{ 
var FloatMenu; 
var stmnLEFT = pstmnLEFT; 
var stmnGAP1 = pstmnGAP1; 
var stmnGAP2 = pstmnGAP2; 
var stmnBASE = pstmnBASE; 
var stmnActivateSpeed = pstmnActivateSpeed; 
var stmnScrollSpeed = pstmnScrollSpeed; 
this.FloatRun=function(pObjName) 
{ 
var newDiv=document.createElement("div"); 
newDiv.id=pObjName; 
newDiv.innerHTML=pText; 
newDiv.style.position="absolute"; 
document.body.appendChild(newDiv); 
FloatMenu=document.getElementById(pObjName); 
FloatMenu.style.display==""; 
FloatMenu.style.top = document.documentElement.scrollTop + stmnBASE+"px"; 
FloatMenu.style.left = stmnLEFT+"px"; 
RefreshStaticMenu(); 
} 
RefreshStaticMenu=function() 
{ 
var stmnStartPoint,stmnEndPoint,stmnRefreshTimer; 
stmnStartPoint = parseInt(FloatMenu.style.top, 10); 
stmnEndPoint = document.documentElement.scrollTop + stmnGAP2; 
if (stmnEndPoint < stmnGAP1) stmnEndPoint = stmnGAP1; 
if(stmnStartPoint != stmnEndPoint) 
{ 
stmnScrollAmount = Math.ceil(Math.abs(stmnEndPoint - stmnStartPoint) / 15 ); 
FloatMenu.style.top = parseInt(FloatMenu.style.top, 10) + ((stmnEndPoint<stmnStartPoint) ? -stmnScrollAmount : stmnScrollAmount)+"px"; 
stmnRefreshTimer = stmnScrollSpeed; 
} 
else 
{ 
stmnRefreshTimer = stmnActivateSpeed; 
} 
setTimeout("RefreshStaticMenu();", stmnRefreshTimer); 
} 
}