function showFlash(){
			// 创建遮罩层
			var _body = document.getElementsByTagName("body")[0];
			if(window.attachEvent){
				var div = document.createElement("<iframe frameborder='0' src='frame.html'></iframe>");
			}else{
				var div = document.createElement("iframe");
				div.src="1.html";
				div.style.border = "0";
			}
			_body.appendChild(div);
			div.setAttribute("id","createDiv");
			var bodyWidth = _body.offsetWidth;
			var bodyHeight = _body.offsetHeight;
			div.style.width = bodyWidth + "px";
			div.style.height = bodyHeight + "px";
			_body.style.height = bodyHeight + "px";
			_body.style.overflow = "hidden";
			div.style.width = bodyWidth + "px";
			div.style.height = bodyHeight + "px";
			div.style.overflow = "hidden";
			div.style.margin = 0;
			div.style.padding = 0;
			div.style.filter = "alpha(opacity=50)";
			
			// 创建 弹出内容层
			var div_1 = document.createElement("div");
			var img = document.createElement("img");
			div_1.setAttribute("id","div_1");
			div_1.appendChild(img);
			_body.appendChild(div_1);
			img.setAttribute("src","images/open.jpg");
			div_1.style.top = bodyHeight/2 - 142 + "px";
			div_1.style.left = bodyWidth/2 - 220 + "px";

			var nodeA = document.createElement("a");
			nodeA.className = "flashA";
			nodeA.setAttribute("title","关闭");
			div_1.appendChild(nodeA);
			nodeA.setAttribute("href","javascript:void(0)");
			
			nodeA.onclick = function (){
				div_1.parentNode.removeChild(div_1);
				div.parentNode.removeChild(div);
				_body.style.overflow = "auto";
			}
		}