有时候感觉alert提示信息过于古板，不太符合需要，那就自己东西写一个吧。先贴代码了，后面会有代码的解释。本人也是刚刚自己总结后写的，对美观方面没有功底，呵呵，就凑合用吧，以后改进。
function Button1_ {
        var msgWidth=400,msgHeight=100,borderColor="#336699";
        var msgSW,msgSH;
        var bigLayout=document.createElement("div");
        bigLayout.setAttribute("id","bigLayout");
        bigLayout.style.position="absolute";
        bigLayout.style.top=0;
        msgSW=document.body.offsetWidth;
        msgSH=document.body.offsetHeight;
        bigLayout.style.width=msgSW;
        bigLayout.style.height=msgSH;
        bigLayout.style.filter="Alpha(opacity=50,finishOpacity=100,style=3)";
        bigLayout.style.zIndex="500";
        document.body.appendChild(bigLayout);
        //上面是定义了一个大的div，用来将整个界面覆盖掉，Alpha是滤镜的东东，百一下就知道参数的含义了。下面就是真正要显示的div，改div有三部分组成，一是标题，二是要提示的信息，这里可以写成传入参数形式的奥。三是两个button按钮，为了实现confirm。

        var msgDiv=document.createElement("div");
        msgDiv.setAttribute("id","msgDiv");
        msgDiv.setAttribute("align","center");
        msgDiv.style.background="white";
        msgDiv.style.height=msgHeight+"px";
        msgDiv.style.width=msgWidth+"px";
        msgDiv.style.position="absolute";
        msgDiv.style.left="50%";
        msgDiv.style.marginLeft=-200;
        msgDiv.style.top="50%";
        msgDiv.style.marginTop=-50+document.body.scrollTop;
        msgDiv.style.zIndex="501";
        //支持拖动，这就不解释了，很简单的，只要看一下setCapture和releaseCapture方法就ok了
        var offX,offY,flag=0;
        msgDiv.onmousedown=function()
        {
            offX=event.x-msgDiv.style.pixelLeft;
            offY=event.y-msgDiv.style.pixelTop;
            flag=1;
        }
        msgDiv.onmousemove=function()
        {
            if(flag==1)
            {
                msgDiv.style.left=event.x-offX;
                msgDiv.style.top=event.y-offY;
                msgDiv.style.position="absolute";
                msgDiv.setCapture();
            }
        }
        msgDiv.onmouseup=function()
        {
            flag=0;
            msgDiv.releaseCapture();
        }
        
        //
        bigLayout.appendChild(msgDiv);
       //追加标题
        var newtitle=document.createElement("h4");
        newtitle.setAttribute("id","msgNewTitle");
        newtitle.setAttribute("align","left");
        newtitle.style.background=borderColor;
        newtitle.style.filter="Alpha(opacity=50,finishOpacity=100,style=1)";
        newtitle.innerText="确认窗口                                                                                  X";
       
        newtitle.style.height="18px";
        newtitle.style.color="black";
        newtitle.style.border="1px solid #336699";
        newtitle.style.padding="3px";
        newtitle.style.font="12px Verdana, Geneva, Arial, Helvetica, sans-serif";
        msgDiv.appendChild(newtitle);
        newtitle.style.cursor="pointer";
        newtitle.onclick=function()         
        {
            document.body.removeChild(bigLayout);
        }
       
       //第二部分，添加提示信息
        var txt=document.createElement("p");
       
        txt.style.padding="2px";
        txt.innerText="this is text info";
        txt.style.font="12px Verdana, Geneva, Arial, Helvetica, sans-serif";
        txt.style.color="black";
        txt.style.cursor="pointer";
        msgDiv.appendChild(txt);
        //第三部分，还是一个div，里面包含两个button
        var divButton=document.createElement("div");
        divButton.style.width="100%";
//        divButton.style.background="red";
        divButton.setAttribute("align","center");
        divButton.style.marginBottom=10;
        var btConfirmY=document.createElement("<input name='btSure' id='btSure' type='button' value='确定' />");
        var btConfirmN=document.createElement("<input name='btCancle' id='btCancle' type='button' value='取消' />");
        btConfirmY.style.marginBottom=2;
        btConfirmY.style.width=60;
        btConfirmY.style.marginRight=20;
        btConfirmN.style.marginBottom=2;
        btConfirmN.style.width=60;
       
        divButton.appendChild(btConfirmY);
        divButton.appendChild(btConfirmN);
       
        msgDiv.appendChild(divButton);