how to Use the debug console

[mhamed]

Can some tell me how we can use the debug console, and its utility
thanx

[BernardChhun]

Ext's debug console or Firefox's debug console (Firebug)??

You can check out the DOM for any css/html errors or modifications.
You can write values in there to check an object attribute using console.log or console.info.
You can check out an object structure (functions & properties)
You can check the time it takes to run into a specific function.
You can check out every XHR call(header, parameters, url)
You can check the time it takes to load your js, css, html file.
You can modify the DOM right on the spot.
You have a javascript console to type in any command

thats mostly what I use :) I'd suggest you take a look at the stickied about Firebug dude