/*
 *Title : 遮罩层插件
 *Author: aioo
 *Date  : 08-08-29
 *QQ    : 624548954
 *Direction: $.layer()  $.removelayer()
 *
 */
(function($){
	$.extend({
		layer:function(){
			if($("#masklayer").length==0){
				$("<div id='masklayer'></div>")
					.css({"width":$(document).width(),"height":$(document).height() + 20,"background":"#000","opacity":"0.8","position":"absolute","top":"0","left":"0","z-index":"50"})
					.appendTo("body");
				if(navigator.appVersion.split(";")[1]==" MSIE 6.0"){
					$("<iframe id='layerFrame'>")
						.css({"width":$(document).width(),"height":$(document).height() + 20,"opacity":"0"})
						.appendTo("#masklayer");
				}
			}else{
				$("#masklayer").show();
			}
		},
		removelayer:function(){
			if($("#masklayer").length!=0){
				$("#masklayer").remove();
			}
		}
	})
})(jQuery);