自己重写了window.alert 方法 望大家疯狂找毛病拍砖啊 帮我解决了

以下是js代码：
window.alert=function(txt)
    {   
    
     var shield = top.window.document.createElement("DIV");
     shield.id = "shield";
     shield.style.position = "absolute";
     shield.style.left = "0px";
     shield.style.top = "0px";
     shield.style.width = "100%";
     shield.style.height =top.window.document.body.scrollHeight+"px";
     shield.style.background = "#333";
     shield.style.textAlign = "center";
     shield.style.zIndex = "10000";
     shield.style.filter = "alpha(opacity=0)";
     var alertFram = top.window.document.createElement("DIV");
     alertFram.className="dragAble";
     alertFram.id="alertFram";
     alertFram.style.position = "absolute";
     alertFram.style.left = "600px";
           alertFram.style.top = "400px";
     alertFram.style.marginLeft = "-225px";
     alertFram.style.marginTop = "-75px";
     alertFram.style.width = "200px";
     alertFram.style.height = "auto";
     alertFram.style.background = "white";
     alertFram.style.textAlign = "center";
     alertFram.style.lineHeight = "150px";
     alertFram.style.zIndex = "10001";
     strHtml="<ul style=\"list-style:none;margin:0px;padding:0px;width:100%;height:auto;border:3px solid #1567ea;border-top:0px solid #1567ea\">\n";
         strHtml+="<li style=\"position: relative ;background-image: url(d-x3.gif);background-repeat:repeat-x;text-align:left;padding-left:10px;font-size:14px;font-weight:bold;height:25px;line-height:25px;\"><div style=\"cursor:default;font:Calibri;color:white;\">Warning</div></li>\n";
strHtml+="<li style=\"background:#fff;text-align:center;font-size:12px;height:auto;line-height:30px;\"><div style=\"cursor:default\">"+txt+"</div></li>\n";
strHtml+="<li style=\"background:#f5f5f5;text-align:center;font-weight:bold;height:25px;line-height:25px; border-top:1px solid #f5f5f5;\"><input type=\"button\" class=\"sbutton\" onMouseOver=\"this.className='button'\" onMouseOut=\"this.className='sbutton'\" value=\"Close\" onclick=\"doOk()\" /></li>\n";
strHtml+="</ul>\n";
     alertFram.innerHTML = strHtml;
     top.window.document.body.appendChild(alertFram);
     top.window.document.body.appendChild(shield);
     var c = 0;
     top.window.doAlpha = function(){
         if (c++>20){self.window.clearInterval(ad);return 0;}
         shield.style.filter = "alpha(opacity=1);";
       
     }
     var ad=self.window.setInterval("parent.doAlpha()",5);
     top.window.doOk=function(){

              alertFram.style.display ="none";
              shield.style.display ="none";
  
       
     }
     alertFram.focus();
     top.window.document.body.onselectstart = function(){return false;};
    
    
    }
    var ie= top.window.document.all;
var nn6= top.window.document.getElementById&&!top.window.document.all;
var isdrag=false;
var y,x;
var oDragObj;

function moveMouse(e) {
if (isdrag) {
oDragObj.style.top  =  (nn6 ? nTY + top.window.e.clientY - y : nTY + top.window.event.clientY - y)+"px";
oDragObj.style.left  =  (nn6 ? nTX + top.window.e.clientX - x : nTX + top.window.event.clientX - x)+"px";
return false;
}
}

function initDrag(e) {
var oDragHandle = nn6 ? top.window.e.target :top.window.event.srcElement;
var topElement = "HTML";
while (oDragHandle.tagName != topElement && oDragHandle.className != "dragAble") {
oDragHandle = nn6 ? oDragHandle.parentNode : oDragHandle.parentElement;
}
if (oDragHandle.className=="dragAble") {
isdrag = true;
oDragObj = oDragHandle;
nTY = parseInt(oDragObj.style.top+0);
y = nn6 ? top.window.e.clientY : top.window.event.clientY;
nTX = parseInt(oDragObj.style.left+0);
x = nn6 ? top.window.e.clientX : top.window.event.clientX;
top.window.document.onmousemove=moveMouse;
return false;
}
}
top.window.document.onmousedown=initDrag;
top.window.document.onmouseup=new Function("isdrag=false");
//-->





将此代码保持为js文件然后导入html中即可
下载为所需的图片
我现在的毛病是将两个连着的alter 同时写就不行了
比如  alter（1）
      alter（2）
希望大家帮我解决啊！！！谢谢啦