Nested IF function with multiple cells for comparison

Thank you for your quick response. Will this work even if there is the possibility of multiple records per ID on sheet2? Allow me to explain my data a little more clearly. Sheet 1 contains Airline reservations by ID # and start / end date. Sheet 2 contains Hotel reservations by ID # with start / end date. I am trying to identify Airline reservations that do not have a hotel reservation. There is a possibility that there will be mutliple hotel reservations per ID that fall within the airline reservation date range. There is also the possibility that there could be a hotel reservation that falls outside of the airline date range. Those hotel reservations that fall outside of the date range don’t matter to me. I am just trying to find a way to identify Airfare by ID without a hotel, without having to manually look at thousands of rows of data. Hopefully that helps to clarify what I am looking at and what I am trying to achieve. Thank you for your help.