function   sAlert(str){ 
    var   msgw,msgh,bordercolor; 
    msgw=400;//提示窗口的宽度 
    msgh=100;//提示窗口的高度 
    titleheight=25   //提示窗口标题高度 
    bordercolor="#336699";//提示窗口的边框颜色 
    titlecolor="#99CCFF";//提示窗口的标题颜色 

    var   sWidth,sHeight; 
    sWidth=document.body.offsetWidth;//浏览器工作区域内页面宽度 
    sHeight=screen.height;//屏幕高度（垂直分辨率） 



    //背景层（大小与窗口有效区域相同，即当弹出对话框时，背景显示为放射状透明灰色） 
    var   bgObj=document.createElement("div");//创建一个div对象（背景层） 
	
    //定义div属性，即相当于 
    // <div   id="bgDiv"   style="position:absolute;   top:0;   background-color:#777;   filter:progid:DXImagesTransform.Microsoft.Alpha(style=3,opacity=25,finishOpacity=75);   opacity:0.6;   left:0;   width:918px;   height:768px;   z-index:10000;"> </div> 
    bgObj.setAttribute("id","bgDiv");
	//alert("***********")
    bgObj.style.position="absolute"; 
    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.left="0"; 
    bgObj.style.width=sWidth   +  "px"; 
    bgObj.style.height=sHeight   +  "px"; 
    bgObj.style.zIndex   =  "10000"; 
    document.body.appendChild(bgObj);//在body内添加该div对象 



    var   msgObj=document.createElement("div")//创建一个div对象（提示框层） 
    //定义div属性，即相当于 
    // <div   id="msgDiv"   align="center"   style="background-color:white;   border:1px   solid   #336699;   position:absolute;   left:50%;   top:50%;   font:12px/1.6em   Verdana,Geneva,Arial,Helvetica,sans-serif;   margin-left:-225px;   margin-top:npx;   width:400px;   height:100px;   text-align:center;   line-height:25px;   z-index:100001;"> </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   =  "50%"; 
    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"; 
    //alert("***********")
    var   title=document.createElement("h4");//创建一个h4对象（提示框标题栏） 
    //定义h4的属性，即相当于 
    // <h4   id="msgTitle"   align="right"   style="margin:0;   padding:3px;   background-color:#336699;   filter:progid:DXImageTransform.Microsoft.Alpha(startX=20,   startY=20,   finishX=100,   finishY=100,style=1,opacity=75,finishOpacity=100);   opacity:0.75;   border:1px   solid   #336699;   height:18px;   font:12px   Verdana,Geneva,Arial,Helvetica,sans-serif;   color:white;   cursor:pointer;"   onclick=""> 关闭 </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="18px"; 
    title.style.font="12px   Verdana,   Geneva,   Arial,   Helvetica,   sans-serif"; 
    title.style.color="white"; 
    title.style.cursor="pointer"; 
    title.innerHTML="关闭"; 
    title.onclick=removeObj; 

    var   button=document.createElement("input");//创建一个input对象（提示框按钮） 
    //定义input的属性，即相当于 
    // <input   type="button"   align="center"   style="width:100px;   align:center;   margin-left:250px;   margin-bottom:10px;"   value="关闭"> 
    button.setAttribute("type","button"); 
    button.setAttribute("value","关闭"); 
    button.style.width="60px"; 
    button.style.align="center"; 
    button.style.marginLeft="250px"; 
    button.style.marginBottom="10px"; 
    button.style.background=bordercolor; 
    button.style.border="1px   solid  "+   bordercolor; 
    button.style.color="white"; 
    button.onclick=removeObj; 
    
    function   removeObj(){//点击标题栏触发的事件 
        document.body.removeChild(bgObj);//删除背景层Div 
        document.getElementById("msgDiv").removeChild(title);//删除提示框的标题栏 
        document.body.removeChild(msgObj);//删除提示框层 
    } 
    document.body.appendChild(msgObj);//在body内添加提示框div对象msgObj 
    document.getElementById("msgDiv").appendChild(title);//在提示框div中添加标题栏对象title 

    var   txt=document.createElement("p");//创建一个p对象（提示框提示信息） 
    //定义p的属性，即相当于 
    // <p   style="margin:1em   0;"   id="msgTxt"> 测试效果 </p> 
    txt.style.margin="1em   0" 
    txt.setAttribute("id","msgTxt"); 
    txt.innerHTML=str;//来源于函数调用时的参数值 
    document.getElementById("msgDiv").appendChild(txt);//在提示框div中添加提示信息对象txt 
    document.getElementById("msgDiv").appendChild(button);//在提示框div中添加按钮对象button 

}