How to check duplicate range of dates while inserting the record

[Gouri]

I am creating roombooking website in asp.net.
and i am facing problem while inserting the record.

eg:
if the room is already booked from 1st march 2010 to 10th march 2010.and if anybody is booking the same room from 4th march to 9th march it should show error message stating that
this room is already booked from 1st march to 10th march.

[Sandeep M]

hi Gouri.. how can we imagine your table structure and process flow. atleast post the tables structure and their relations...