//获取页面中心位置
function getMouseSite(){
	var site = new Array();
	if(document.all){
        winW = document.documentElement.clientWidth;	//窗口可见宽度
        winH = document.documentElement.clientHeight;	//窗口可见高度
        broY = document.documentElement.scrollTop;		//页面滚动的高度
	}else{
        winW = window.innerWidth;	//窗口可见宽度
        winH = window.innerHeight;	//窗口可见高度
        broY = window.pageYOffset;	//页面滚动的高度
	}
    site["left"] = winW/2;
    site["top"] = winH+broY-500;
	return site;
}

function getClientSize(){
	var size =new Array();
	var height = document.body.clientHeight;
	var width = document.body.clientWidth;
	size["height"] = height;
	size["width"] = width;
	return size;
}