Help: room booking

Hello
I have a work sheet to hotel reservation, one for room reservation entry clients data, and one for the calendar.
I need your help to make the name of the clients or room number in (Room reservation sheet) appear automatically in (Availability sheet) calendar.

This is the formula in calender (availability sheet)

=IF(AND($B8<>"",$C8<>""),1-SUMPRODUCT(('Room Reservation'!$F$2:$F$1000<=E$7)*('Room Reservation'!$G$2:$G$1000>=E$7+1)*('Room Reservation'!$J$2:$J$1000=$B8)*('Room Reservation'!$K$2:$K$1000=$C8)),"")

Thank you

We understand the concept but there is no way to give you a solution without seeing how all of your data is arranged.

Please attach your file. See yellow banner at the top of the page.

Welcome to the forum.

There are instructions at the top of the page explaining how to attach your sample workbook (in a yellow banner).

A good sample workbook has just 10-20 rows of representative data. It also has expected results mocked up, relevant cells highlighted and a few explanatory notes.