function AlertMsg() {
    if (!getCookie("tjwpopup")) {
        var sWidth, sHeight;
        sWidth = window.screen.availWidth;
        if (window.screen.availHeight > document.body.scrollHeight) {
            sHeight = window.screen.availHeight;
        } else {
            sHeight = document.body.scrollHeight;
        }
        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";
        document.body.appendChild(maskObj);

        var MyDiv = document.getElementById("MyDiv");
        var MyDiv_w = getStyle(MyDiv, "width");
        var MyDiv_h = getStyle(MyDiv, "height");

        MyDiv_w = parseInt(MyDiv_w);
        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);
        var Div_leftposition = left + (width / 2) - (MyDiv_w / 2);

        MyDiv.style.left = Div_leftposition + "px";
        MyDiv.style.top = Div_topposition + "px";
        MyDiv.style.display = "block";
    }
}

function CloseDiv() {
    var isShow = document.getElementById("ckbIsShow").checked;
    if (isShow) {
        setCookie("tjwpopup", "true", 30);
    }

    var Bigdiv = document.getElementById("BigDiv");
    var Mydiv = document.getElementById("MyDiv");
    document.body.removeChild(Bigdiv);
    Mydiv.style.display = "none";
}


function pageWidth() {
    return window.innerWidth != null ? window.innerWidth : document.documentElement && document.documentElement.clientWidth ? document.documentElement.clientWidth : document.body != null ? document.body.clientWidth : null;
}


function pageHeight() {
    return window.innerHeight != null ? window.innerHeight : document.documentElement && document.documentElement.clientHeight ? document.documentElement.clientHeight : document.body != null ? document.body.clientHeight : null;
}

function topPosition() {
    return typeof window.pageYOffset != 'undefined' ? window.pageYOffset : document.documentElement && document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop ? document.body.scrollTop : 0;
}


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 getStyle(elem, name) {
    if (elem.style[name])
        return elem.style[name];
    else if (elem.currentStyle)
        return elem.currentStyle[name];
    else if (document.defaultView && document.defaultView.getComputedStyle) {
        name = name.replace(/([A-Z])/g, "-$1");
        name = name.toLowerCase();

        var s = document.defaultView.getComputedStyle(elem, "");
        return s && s.getPropertyValue(name);
    } else
        return null
}

function setCookie(c_name, value, expiredays) {
    var exdate = new Date()
    exdate.setDate(exdate.getDate() + expiredays)
    document.cookie = c_name + "=" + escape(value) +
            ((expiredays == null) ? "" : ";expires=" + exdate.toGMTString())
}
function getCookie(c_name) {
    if (document.cookie.length > 0) {
        c_start = document.cookie.indexOf(c_name + "=")
        if (c_start != -1) {
            c_start = c_start + c_name.length + 1
            c_end = document.cookie.indexOf(";", c_start)
            if (c_end == -1) c_end = document.cookie.length
            return unescape(document.cookie.substring(c_start, c_end))
        }
    }
    return ""
}