How to save data in database at browser close

Hi All,

        I am regular reader of this site, every post of this site is unique and have minimum line of code. so thanks for all who have posted blog at this site.
 
                   At current time i am facing problem related to the saving data in web-application when browser is closed by user.i.e. how to save the data automatically in database when user close browser(click at X or atl+f4). 

                     If any one have some time for this then please must post the solution of this.