如何使一个DIV上下卷动...

Question

//--------------------------------------------------------------------------------------------
var d_posHeight=new Array();
function showDiv(a){
if(timer)clearInterval(timer);
var pThisParent=a.parentNode;
var pThis=pThisParent.id.substr(0,pThisParent.id.indexOf('_show'));
pThis=getSignID(pThis+'_x');//aa
var pThis_f=pThis.offsetHeight;
var pThis_h;
var pThis_i;
if(pThis.style.overflow=="hidden"){
pThis_h=d_posHeight[pThis.id];
pThis_i="visible";
}else{
pThis_h=0;
pThis_i="hidden";
d_posHeight[pThis.id]=pThis_f;
}
var pThis_k=100;
var v=10;
var i=0;
timer=setInterval(function(){
var pThis_x=i/v;
var pThis_C=pThis_f+(pThis_h-pThis_f)*pThis_x;
pThis.style.height=parseInt(pThis_C)+'px';
i++;
if(pThis_x>=1){
pThis.style.overflow=pThis_i
clearInterval(timer);
}
},pThis_k/v);
return false;
}这个是看GOOGLE改的。