function openLayer(conId){	
	var arrayPageSize   = getPageSize();//调用getPageSize()函数
	var arrayPageScroll = getPageScroll();//调用getPageScroll()函数
	var popupDiv = document.getElementById(conId)
	//创建弹出背景层以及设置属性与样式
	if(!document.getElementById("bodybg")){
		var bodyBack = document.createElement("div");	
		document.body.appendChild(bodyBack);	
		bodyBack.setAttribute("id","bodybg")
		bodyBack.style.position = "absolute";
		bodyBack.style.width = (arrayPageSize[0] + 0 + 'px');
		bodyBack.style.height = (arrayPageSize[1] + 0 + 'px');
		bodyBack.style.zIndex = 2999;
		bodyBack.style.top = 0;
		bodyBack.style.left = 0;
		bodyBack.style.filter = "alpha(opacity=70)";
		bodyBack.style.opacity = 0.7;
		bodyBack.style.background = "#000";
	}
	//显示背景层
	document.getElementById("bodybg").style.display = "";
	//显示内容层
	popupDiv.style.display = "";
	//设置弹出层属性与样式,居中显示
	popupDiv.style.top = arrayPageScroll[1] + (arrayPageSize[3] - popupDiv.offsetHeight) / 2 + 'px';
	popupDiv.style.left = (arrayPageSize[0] - popupDiv.offsetWidth) / 2 + 'px';
	popupDiv.style.zIndex = 3000;	
}
//获取滚动条的高度
function getPageScroll(){
	var yScroll;
	if (self.pageYOffset) {
		yScroll = self.pageYOffset;
	} else if (document.documentElement && document.documentElement.scrollTop){
		yScroll = document.documentElement.scrollTop;
	} else if (document.body) {
		yScroll = document.body.scrollTop;
	}
	arrayPageScroll = new Array('',yScroll)
	return arrayPageScroll;
}
//获取页面实际大小
function getPageSize(){
	var xScroll,yScroll;
	if (window.innerHeight && window.scrollMaxY){
		xScroll = document.body.scrollWidth;
		yScroll = window.innerHeight + window.scrollMaxY;
	} else if (document.body.scrollHeight > document.body.offsetHeight){
		sScroll = document.body.scrollWidth;
		yScroll = document.body.scrollHeight;
	} else {
		xScroll = document.body.offsetWidth;
		yScroll = document.body.offsetHeight;
	}
	var windowWidth,windowHeight;
	//var pageHeight,pageWidth;
	if (self.innerHeight) {
		windowWidth = self.innerWidth;
		windowHeight = self.innerHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) {
		windowWidth = document.documentElement.clientWidth;
		windowHeight = document.documentElement.clientHeight;
	} else if (document.body) {
		windowWidth = document.body.clientWidth;
		windowHeight = document.body.clientHeight;
	}
	var pageWidth,pageHeight
	if(yScroll < windowHeight){
		pageHeight = windowHeight;
	} else {
		pageHeight = yScroll;
	}
	if(xScroll < windowWidth) {
		pageWidth = windowWidth;
	} else {
		pageWidth = xScroll;
	}
	arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight)
	return arrayPageSize;
}
//关闭弹出层
function closeLayer(conId){
	document.getElementById(conId).style.display = "none";
	document.getElementById("bodybg").style.display = "none";
	return false;
}