layer.confirm快速多次点击会重复触发事件问题

function a () {
            console.log("请求开始---");           	                                    
            var lock=false;//默认未锁定
            var myconfirm=layer.confirm('是否确认?',{btn: ['确定','取消']},function(index){
                        console.log(lock);
                         if(!lock){
                        	 lock=true;//锁定
                             //发送ajax
                               $.ajax({
                                   url:  '/../../outBoundByTask',
                                   isAysn: false,
                                   type: 'get',
                                   contentType: 'application/json',
                                   data:params.join('&'),
                                   success: function (result) {
                                                          	
                                   	var res=$.parseJSON(result);
                                    var code=res.code;
                                    	if(code==0){
                                    		layer.msg("操作成功！");
                                    		window.location.reload();
                                    	}else{
                                    		layer.msg(res.msg);
                                    	}
                                   }
                               });
                         }
                        }
                        ,function(index){
                          console.log('fail');
                        });
                }