Search the entry for the default web browser

[siddharth]

Hello everybody,
                       One can set the default web browser in his system. You could be of great help to me by letting me know as to where are the enteries pertaining to the default web browser contained. And as to how can we launch that default web browser by code once the default web browser is known.   Thanks in advance.
                                                                                Siddharth.