function
getByClass(oParent,sClass){
var
aEle=oParent.getElementsByTagName('*');
var
aTmp=[];
var
i=0;
for
(i=0;i<aEle.length;i++){
if
(aEle[i].className==sClass){
aTmp.push(aEle[i]);
}
}
return
aTmp;
}
var
op = document.getElementById('p1');
var
oMark = getByClass(op,'mark')[0];
var
oFloat=getByClass(op,'float_layer')[0];
var
oBg=getByClass(op,'big_pic')[0];
var
oSm=getByClass(op,'small_pic')[0];
var
oImg=oBg.getElementsByTagName('img')[0];
oMark.onmouseover=
function
(){
oFloat.style.display='block';
oBg.style.display='block';
}
oMark.onmouseout=
function
(){
oFloat.style.display='none';
oBg.style.display='none';
}
oMark.onmousemove=
function
(ev){
var
oEvent=ev||event;
var
disX=oEvent.clientX-op.offsetLeft-oSm.offsetLeft-oFloat.offsetWidth/2;
var
disY=oEvent.clientY-op.offsetTop-oSm.offsetTop-oFloat.offsetHeight/2;
var
l=disX, t=disY;
l<0?l=0:l>(oMark.offsetWidth-oFloat.offsetWidth)?l=oMark.offsetWidth-oFloat.offsetWidth:l=disX;
t<0?t=0:t>(oMark.offsetWidth-oFloat.offsetHeight)?t=oMark.offsetWidth-oFloat.offsetHeight:t=disY;
oFloat.style.left=l+'px';
oFloat.style.top=t+'px';
var
percentX=l/(oMark.offsetWidth-oFloat.offsetWidth);
var
percentY=t/(oMark.offsetHeight-oFloat.offsetHeight);
oImg.style.left=-(oImg.offsetWidth-oBg.offsetWidth)*percentX +'px';
oImg.style.top=-(oImg.offsetHeight-oBg.offsetHeight)*percentY +'px';
}