Everyone should know about Firebug for Mozilla by now. I had the problem not being able to use ‘console.log()’ on IE.

Here’s a quick solution, a wonderful package log4javascript by Tim Down.

I used wrapper class to switch between the two on different browsers.

if(navigator.userAgent.indexOf("Firefox") == -1) {
// Create the logger. "mylogger" is the unique name of the logger and
// can be any string.
var log = log4javascript.getLogger("mylogger");// Create a PopUpAppender with default options
var popUpAppender = new log4javascript.PopUpAppender();

// Change the desired configuration options
popUpAppender.setFocusPopUp(true);
popUpAppender.setNewestMessageAtTop(true);

// Add the appender to the logger
log.addAppender(popUpAppender);

var console = Class.create();
console.log = function(s) { log.debug(s);  }
console.debug = function(s) { log.debug(s);  }
console.info = function(s) { log.info(s);  }
console.warn = function(s) { log.warn(s);  }
console.error = function(s) { log.error(s);  }
}