function $(nodeId)
{
return document.getElementById(nodeId);
}
function loading()
{
var width = "160";
var height = "16";
var loadheight = "16"; // 提示窗口标题高度 
var loadimage = "images/loading.gif"; 
var titlebgcolor = "#666699"; // 提示窗口的标题背景色
var bgcolor = "#FFFFFF"; // 提示内容的背景色

var sctop = document.body.scrollTop;
var iHeight = window.screen.height;
iHeight = (iHeight-height)/2;
sctop = iHeight+sctop;
var iWidth = document.body.clientWidth;

var bgObj = document.createElement("div");
bgObj.id = "div_grey";
bgObj.style.cssText = "position:absolute;left:0px;top:0px;width:"+iWidth+"px;height:"+Math.max(document.body.clientHeight, iHeight)+"px;filter:Alpha(Opacity=10);opacity:0.1;background-color:#FFF;z-index:101;";
document.body.appendChild(bgObj);

var msgObj = document.createElement("div");
msgObj.id = "window_box";
msgObj.style.cssText = "position:absolute;font:11px '宋体';top:" + sctop + "px;left:" + (iWidth - width) / 2 + "px;width:" + width + "px;height:" + height + "px;text-align:center;background-color:" + bgcolor + "; z-index:102;";
document.body.appendChild(msgObj);

var titleObj = document.createElement("div");
titleObj.id = "title_box";
titleObj.style.cssText = "width:100%; height:" + loadheight +"px; line-height:" + loadheight + "px; background-IMAGE:url(" + loadimage + ");";
msgObj.appendChild(titleObj);
}
function close_loading(obj_1,obj_2,obj_3)
{
$(obj_1).style.display = "none";
$(obj_2).style.display = "none";
$(obj_2).removeChild($(obj_3));
document.body.removeChild($(obj_1));
document.body.removeChild($(obj_2));
}