function sAlert(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);
}