function CustomAlert(msgStr)
{ 
    var msgw = 600;  // 消息窗口宽度
    var msgh = 220;  // 消息窗口高度
    var bordercolor = "#336699"; // 消息边框色
    var titlecolor = "#99CCFF";  // 标题栏着色
    var titleheight = 18;        // 标题栏高度

    //遮罩层
    var sWidth = document.body.clientWidth; 
    var sHeight = document.body.clientHeight; 
    var bgObj = document.createElement("div"); 
    bgObj.setAttribute('id','bgDiv'); 
    bgObj.style.position = "absolute"; 
    bgObj.style.left = "0"; 
    bgObj.style.top = "0";   
    bgObj.style.background = "#777"; 
    bgObj.style.filter = "progid:DXImageTransform.Microsoft.Alpha(style=3,opacity=25,finishOpacity=75)";
    bgObj.style.opacity = "0.6";  
    bgObj.style.width = sWidth + "px"; 
    bgObj.style.height = sHeight + "px";  
    bgObj.style.zIndex = "10000"; 
    document.body.appendChild(bgObj);

    //消息内容
    var msgObj = document.createElement("div"); 
    msgObj.setAttribute("id","msgDiv"); 
    msgObj.setAttribute("align","center"); 
    msgObj.style.background = "white"; 
    msgObj.style.border = "1px solid " + bordercolor; 
    msgObj.style.position = "absolute"; 
    msgObj.style.left = "50%"; 
    msgObj.style.top = "30%"; 
    msgObj.style.font = "12px/1.6em Verdana, Geneva, Arial, Helvetica, sans-serif";
    msgObj.style.marginLeft = "-225px" ; 
    msgObj.style.marginTop = -75 + document.documentElement.scrollTop + "px"; 
    msgObj.style.width = msgw + "px"; 
    msgObj.style.height = msgh + "px"; 
    msgObj.style.textAlign = "center"; 
    msgObj.style.lineHeight = "25px"; 
    msgObj.style.zIndex = "10001"; 

    //标题栏
    var title=document.createElement("h4"); 
    title.setAttribute("id","msgTitle"); 
    title.setAttribute("align","right"); 
    title.style.margin = "0"; 
    title.style.padding = "3px"; 
    title.style.background = bordercolor;
    title.style.filter = "progid:DXImageTransform.Microsoft.Alpha(startX=20, startY=20, finishX=100, finishY=100,style=1,opacity=75,finishOpacity=100);";   
    title.style.opacity = "0.75"; 
    title.style.border = "1px solid " + bordercolor; 
    title.style.height = titleheight + "px"; 
    title.style.font = "12px Verdana, Geneva, Arial, Helvetica, sans-serif"; 
    title.style.color = "white"; 
    title.style.cursor = "pointer"; 
    title.innerHTML = "关闭"; 
    title.onclick = function()
    { 
          document.body.removeChild(bgObj); //移除遮罩层
          document.getElementById("msgDiv").removeChild(title); //移除标题栏
          document.body.removeChild(msgObj); //移除消息内容
    } 

    //将消息窗口(标题栏和消息内容)添加到页面中去
    document.body.appendChild(msgObj); 
    msgObj.appendChild(title); 
    var txt = document.createElement("p"); 
    txt.style.margin = "1em 0";
    txt.setAttribute("id","msgTxt"); 
    txt.innerHTML = msgStr;
    msgObj.appendChild(txt); 
}