//启用javascript 日志功能

var logger = log4javascript.getLogger("main");

log4javascript.setEnabled(true);

var appender = new log4javascript.InPageAppender();

appender.layout.pattern = '%d{yyyy-MM-dd HH:mm:ss,SSS} [%c] %-5p - %m{1}%n';

logger.addAppender(appender);

//点击Ctrl键时显示/隐藏日志控制台

document.onkeydown = function (evt) {

    var VK_F9 = 120;

    //兼容IE和Firefox获得keyBoardEvent对象

    var evt = (evt) ? evt : ((window.event) ? window.event : "");

    //兼容IE和Firefox获得keyBoardEvent对象的键值

    var key = evt.keyCode ? evt.keyCode : evt.which;

    if (evt.ctrlKey) {

        if (appender.visible) {

            appender.hide();

            appender.visible = false;

            log4javascript.setEnabled(false);

        } else {

            log4javascript.setEnabled(true);

            appender.show();

            appender.visible = true;

        }

    }

};

<script src="~/Content/Third/log4javascript-1.4.2/log4javascript.js"></script>

<script src="~/Scripts/Common/log4jsService.js"></script>

  $(function () {

        $("#Button1").click(function () {

            logger.debug("This is a debugging message from the log4javascript in-page page");

            logger.info("info info");

            logger.error("error info");

        });

    });