//创建遮罩层

      //创建遮罩层

var Drag = {

    obj: null,

    init: function(o, oRoot, minX, maxX, minY, maxY, bSwapHorzRef, bSwapVertRef, fXMapper, fYMapper) {
        o.onmousedown = Drag.start;

        o.hmode = bSwapHorzRef ? false : true;
        o.vmode = bSwapVertRef ? false : true;

        o.root = oRoot && oRoot != null ? oRoot : o;

        if (o.hmode && isNaN(parseInt(o.root.style.left))) o.root.style.left = "0px";
        if (o.vmode && isNaN(parseInt(o.root.style.top))) o.root.style.top = "0px";
        if (!o.hmode && isNaN(parseInt(o.root.style.right))) o.root.style.right = "0px";
        if (!o.vmode && isNaN(parseInt(o.root.style.bottom))) o.root.style.bottom = "0px";

        o.minX = typeof minX != 'undefined' ? minX : null;
        o.minY = typeof minY != 'undefined' ? minY : null;
        o.maxX = typeof maxX != 'undefined' ? maxX : null;
        o.maxY = typeof maxY != 'undefined' ? maxY : null;

        o.xMapper = fXMapper ? fXMapper : null;
        o.yMapper = fYMapper ? fYMapper : null;

        o.root.onDragStart = new Function();
        o.root.onDragEnd = new Function();
        o.root.onDrag = new Function();
    },

    start: function(e) {
        var o = Drag.obj = this;
        e = Drag.fixE(e);
        var y = parseInt(o.vmode ? o.root.style.top : o.root.style.bottom);
        var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right);
        o.root.onDragStart(x, y);

        o.lastMouseX = e.clientX;
        o.lastMouseY = e.clientY;

        if (o.hmode) {
            if (o.minX != null) o.minMouseX = e.clientX - x + o.minX;
            if (o.maxX != null) o.maxMouseX = o.minMouseX + o.maxX - o.minX;
        } else {
            if (o.minX != null) o.maxMouseX = -o.minX + e.clientX + x;
            if (o.maxX != null) o.minMouseX = -o.maxX + e.clientX + x;
        }

        if (o.vmode) {
            if (o.minY != null) o.minMouseY = e.clientY - y + o.minY;
            if (o.maxY != null) o.maxMouseY = o.minMouseY + o.maxY - o.minY;
        } else {
            if (o.minY != null) o.maxMouseY = -o.minY + e.clientY + y;
            if (o.maxY != null) o.minMouseY = -o.maxY + e.clientY + y;
        }

        document.onmousemove = Drag.drag;
        document.onmouseup = Drag.end;

        return false;
    },

    drag: function(e) {
        e = Drag.fixE(e);
        var o = Drag.obj;

        var ey = e.clientY;
        var ex = e.clientX;
        var y = parseInt(o.vmode ? o.root.style.top : o.root.style.bottom);
        var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right);
        var nx, ny;

        if (o.minX != null) ex = o.hmode ? Math.max(ex, o.minMouseX) : Math.min(ex, o.maxMouseX);
        if (o.maxX != null) ex = o.hmode ? Math.min(ex, o.maxMouseX) : Math.max(ex, o.minMouseX);
        if (o.minY != null) ey = o.vmode ? Math.max(ey, o.minMouseY) : Math.min(ey, o.maxMouseY);
        if (o.maxY != null) ey = o.vmode ? Math.min(ey, o.maxMouseY) : Math.max(ey, o.minMouseY);

        nx = x + ((ex - o.lastMouseX) * (o.hmode ? 1 : -1));
        ny = y + ((ey - o.lastMouseY) * (o.vmode ? 1 : -1));

        if (o.xMapper) nx = o.xMapper(y)
        else if (o.yMapper) ny = o.yMapper(x)

        Drag.obj.root.style[o.hmode ? "left" : "right"] = nx + "px";
        Drag.obj.root.style[o.vmode ? "top" : "bottom"] = ny + "px";
        Drag.obj.lastMouseX = ex;
        Drag.obj.lastMouseY = ey;

        Drag.obj.root.onDrag(nx, ny);
        return false;
    },

    end: function() {
        document.onmousemove = null;
        document.onmouseup = null;
        Drag.obj.root.onDragEnd(parseInt(Drag.obj.root.style[Drag.obj.hmode ? "left" : "right"]),
									parseInt(Drag.obj.root.style[Drag.obj.vmode ? "top" : "bottom"]));
        Drag.obj = null;
    },

    fixE: function(e) {
        if (typeof e == 'undefined') e = window.event;
        if (typeof e.layerX == 'undefined') e.layerX = e.offsetX;
        if (typeof e.layerY == 'undefined') e.layerY = e.offsetY;
        return e;
    }
};

/**第三步：关闭窗口和遮罩层。*/
function CloseDiv(id) {
    var Bigdiv = document.getElementById("BigDiv");
    var Mydiv = document.getElementById(id);
    document.body.removeChild(Bigdiv);
    Mydiv.style.display = "none";
}
/** 第四步：弹出层拖动。*/
window.onload = function() {

   if (document.getElementById("MyDiv1")) {
        var MyDiv = document.getElementById("MyDiv1");
        var dragMe = document.getElementById("dragMe1");
        Drag.init(dragMe, MyDiv);
    }
    
   if (document.getElementById("needMail")) {
        var MyDiv = document.getElementById("needMail");
        var dragMe = document.getElementById("needMail_title");
        Drag.init(dragMe, MyDiv);
    }
    


 
}

/**第五步：弹出层跟随滚动条滚动。*/
window.onscroll = window_all;

function window_all(){

window_onscroll("MyDiv1");
window_onscroll("needMail");

}
function window_onscroll(id) {
    var MyDiv = document.getElementById(id);
    var MyDiv_h = getStyle(MyDiv, "height");
    MyDiv_h = parseInt(MyDiv_h);
    var height = pageHeight();
    var top = topPosition();
    var Div_topposition = top + (height / 2) - (MyDiv_h / 2); //计算上边距
    MyDiv.style.top = Div_topposition + "px";



 
}

/**
下面都是常用函数，已经收录在我的jsskep.js中。可以在里面找到。
工程地址：http://code.google.com/p/jsskep/
**/
// 计算当前窗口的宽度 //
function pageWidth() {
    return window.innerWidth != null ? window.innerWidth : document.documentElement && document.documentElement.clientWidth ? document.documentElement.clientWidth : document.body != null ? document.body.clientWidth : null;
}

// 计算当前窗口的高度 //
function pageHeight() {
    return window.innerHeight != null ? window.innerHeight : document.documentElement && document.documentElement.clientHeight ? document.documentElement.clientHeight : document.body != null ? document.body.clientHeight : null;
}

// 计算当前窗口的上边滚动条//
function topPosition() {
    return typeof window.pageYOffset != 'undefined' ? window.pageYOffset : document.documentElement && document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop ? document.body.scrollTop : 0;
}

// 计算当前窗口的左边滚动条//
function leftPosition() {
    return typeof window.pageXOffset != 'undefined' ? window.pageXOffset : document.documentElement && document.documentElement.scrollLeft ? document.documentElement.scrollLeft : document.body.scrollLeft ? document.body.scrollLeft : 0;
}




        function AlertMsg(id) {


            /**第一步：创建DIV遮罩层。*/
            var sWidth, sHeight;
            sWidth = window.screen.availWidth;
            //屏幕可用工作区高度： window.screen.availHeight;
            //屏幕可用工作区宽度： window.screen.availWidth;
            //网页正文全文宽：     document.body.scrollWidth;
            //网页正文全文高：     document.body.scrollHeight;
            if (window.screen.availHeight > document.body.scrollHeight) {  //当高度少于一屏
                sHeight = window.screen.availHeight;
            } else {//当高度大于一屏
                sHeight = document.body.scrollHeight;
            }
            //创建遮罩背景
           // var maskObj = document.createElement("div");
//            maskObj.setAttribute('id', 'BigDiv');
//            maskObj.style.position = "absolute";
//            maskObj.style.top = "0";
//            maskObj.style.left = "0";
//            maskObj.style.background = "#777";
//            maskObj.style.filter = "Alpha(opacity=30);";
//            maskObj.style.opacity = "0.3";
//            maskObj.style.width = sWidth + "px";
//            maskObj.style.height = sHeight + "px";
//            maskObj.style.zIndex = "10000";
	//var	maskObj ="<div id='BigDiv'  style=' position:absolute; top:0px; left:0px;background:#777;filter:Alpha(opacity=30);opacity:0.3; width:"+sWidth +"px; height:"+sHeight+"px; z-index:10000'></div>";
			
           // document.body.appendChild(maskObj);
		   
		   
		   	var	maskObj ="<div id='BigDiv'  style=' position:absolute; top:0px; left:0px;background:#777;filter:Alpha(opacity=30);opacity:0.3; width:"+sWidth +"px; height:"+sHeight+"px; z-index:10000'><iframe style=\"width:100%;height:100%;border:none;filter:alpha(opacity=0);opacity:0;\"></iframe></div>";
          $("body").append(maskObj);
            

            /**第二步：动态设置div的上边距和左边距，使弹出div居中打开。*/
            var MyDiv = document.getElementById(id);
            var MyDiv_w = getStyle(MyDiv, "width");
            var MyDiv_h = getStyle(MyDiv, "height");

            MyDiv_w = parseInt(MyDiv_w); //去掉 单位 "px"
            MyDiv_h = parseInt(MyDiv_h);

            var width = pageWidth();
            var height = pageHeight();
            var left = leftPosition();
            var top = topPosition();

            var Div_topposition = top + (height / 2) - (MyDiv_h / 2); //计算上边距
            var Div_leftposition = left + (width / 2) - (MyDiv_w / 2); //计算左边距

            MyDiv.style.left = Div_leftposition + "px";  //拼接上 单位"px"
            MyDiv.style.top = Div_topposition + "px";
            MyDiv.style.display = "block";  //设置弹出div显示
        }