/*-------------------------鼠标左键拖动---------------------*/
/*--------当不需要实现此功能时，可以将这一部分代码删除------------*/
var objDiv = document.getElementById("popDiv");
var isIE = document.all ? true : false;//判断浏览器类型
document.onmousedown = function(evnt) {//当鼠标左键按下后执行此函数
var evnt = evnt ? evnt : event;
if (evnt.button == (document.all ? 1 : 0)) {
mouseD = true;//mouseD为鼠标左键状态标志，为true时表示左键被按下
}
}

objDiv.onmousedown = function(evnt) {
objDrag = this;//objDrag为拖动的对象
var evnt = evnt ? evnt : event;
if (evnt.button == (document.all ? 1 : 0)) {
mx = evnt.clientX;
my = evnt.clientY;
objDiv.style.left = objDiv.offsetLeft + "px";
objDiv.style.top = objDiv.offsetTop + "px";
if (isIE) {
objDiv.setCapture();
//objDiv.filters.alpha.opacity = 50;//当鼠标按下后透明度改变
} else {
window.captureEvents(Event.MOUSEMOVE);//捕获鼠标拖动事件
//objDiv.style.opacity = 0.5;//当鼠标按下后透明度改变
}
}
}
document.onmouseup = function() {
mouseD = false;//左键松开
objDrag = "";
if (isIE) {
objDiv.releaseCapture();
//objDiv.filters.alpha.opacity = 100;//当鼠标左键松开后透明度改变
} else {
window.releaseEvents(objDiv.MOUSEMOVE);//释放鼠标拖动事件
//objDiv.style.opacity = 1;//当鼠标左键松开后透明度改变
}
}

document.onmousemove = function(evnt) {
var evnt = evnt ? evnt : event;
if (mouseD == true && objDrag) {
var mrx = evnt.clientX - mx;
var mry = evnt.clientY - my;
objDiv.style.left = parseInt(objDiv.style.left) + mrx + "px";
objDiv.style.top = parseInt(objDiv.style.top) + mry + "px";
mx = evnt.clientX;
my = evnt.clientY;
}
}