DIV形式的alert提示效果--JS源码

调用方法:
<input type="button" value="点击我就看到效果了哦``" onclick=" DIVAlert ('测试!!!');" />

JS源码:
<script type="text/javascript" language="javascript">
      function DIVAlert(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;
      sHeight=screen.height;

      var bgObj=document.createElement("div");
      bgObj.setAttribute('id','bgDiv');
      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);
   
      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 = "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";
   
        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="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=function(){
             document.body.removeChild(bgObj);
                   document.getElementById("msgDiv").removeChild(title);
                   document.body.removeChild(msgObj);
                   }
        document.body.appendChild(msgObj);
        document.getElementById("msgDiv").appendChild(title);
        var txt=document.createElement("p");
        txt.style.margin="1em 0"
        txt.setAttribute("id","msgTxt");
        txt.innerHTML=str;
              document.getElementById("msgDiv").appendChild(txt);
               }
     </script>