友好的alert

<script>
         function sAlert(str){ 
          var msgw,msgh,bordercolor; 
          msgw=400;//Width
          msgh=100;//Height 
          titleheight=25 //title Height
          bordercolor="#336699";//boder color
          titlecolor="#99CCFF";//title color

          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 = "fixed"; 
          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> <input type="button" value="click" onclick="sAlert('123');" />