//多物体运动框架
function startMove(obj,attr,iTarget){
clearInterval(obj.timer);
obj.timer=setInterval(function(){
var cur=0;
if(attr=='opacity'){
cur=Math.round(parseFloat(getStyle(obj,attr))*100);
}else{
cur=parseInt(getStyle(obj,attr));
}
var speed=(iTarget-cur)/6
speed=speed>0?Math.ceil(speed):Math.floor(speed);
if (cur==iTarget) {
clearInterval(obj.timer);
}else{
if(attr=='opacity'){
obj.style.opacity=(cur+speed)/100;
obj.style.filter='alpha(opacity:'+(cur+speed)+');';
}else{
obj.style[attr]=cur+speed+'px';
}
}
},30);
}
function getStyle(obj,name){
if (obj.currentStyle) {
return obj.currentStyle[name];//用点号会怎样
}else{
return getComputedStyle(obj,false)[name];
}
}