Here is what you do to make an availability change in the Members Area. This can be done to close out dates when you are booked:
1) Login to the Members Area at: https://members.bookingcenter.com
2) Click Availability /Rates tab, then 'Update Availability' page.
3) Choose the weeks you wish to manage, such as the dates May 15 - 30
4) Put how many rooms you have left in each cell. If you wish to 'close out', then place a 0 in each day's field.
5) Click 'Update All' after making your change to save the results.
This will close out those days or make the numbers you placed the correct rooms to sell for those days.