像百度知道中，点击我要提问，弹出一个“知道提示”整个页面变模糊，请问这个在asp.net怎么实现？

给你一个现成的 ：
var divh=140;
var divw=333;
function cart(good_list_id,method){
var sWidth,sHeight;
if (window.ActiveXObject){
sWidth=document.documentElement.scrollWidth;
sHeight=document.documentElement.scrollHeight>document.documentElement.clientHeight?document.documentElement.scrollHeight:document.documentElement.clientHeight;
}
else{
sWidth=document.documentElement.scrollWidth;
//sHeight=document.body.clientHeight;
sHeight=document.body.clientHeight>document.documentElement.clientHeight?document.body.clientHeight:document.documentElement.clientHeight;
}
//alert(sHeight);
var bgObj=document.createElement("div");
bgObj.setAttribute('id','bgDiv');
bgObj.style.position="absolute";
bgObj.style.top="0";
bgObj.style.background="#DDD";
bgObj.style.filter="progid:DXImageTransform.Microsoft.Alpha(style=3,opacity=25,finish