screen display problem

It sounds like your cleaning solution may have leaked inside and damaged the screen.  See what the image looks like on an external monitor.  If it's OK there, the panel will need to be replaced -- it's unlikely that Dell will cover this even if it's under warranty (unless you have accidental damage coverage).

sir, my laptop's warranty has expired . I notice that my screen is adjusting (improving) itself .The problem of screen area decrease 80% to 60% ( 20% of minimum affected area has adjusted  itself ) in last 36 hours but major affected  area is still in position. i think , the liquid of LED screen had displaced its position looks like while throwing water on the tiles floor and how it scatter . The internal light  of screen transparent between this gap. there is no other problem except this.

                    Sir plz  advice me ,what should i do ? should i go to dell service center  and where it is  Patna, Bihar ? and Plz also advice me  what should i use to wipe screen in future so that my screen remain safe at any circumstances .

Any computer shop can change the screen - which is what is needed.  Once it's replaced, to clean it use  a damp cloth - do not spray liquid directly onto the screen.