Help with SQL Statement

Hi,
I have the following stored procedure, which is working fine:

(
    @BookingDate DATETIME,
    @BookingStart DATETIME,
    @BookingEnd DATETIME,
    @RoomOpening DATETIME,
    @RoomClosing DATETIME,
    @Attendees INT,
    @SiteID INT,
    @IsCatering varchar(50)
    )
    
AS

SELECT Rooms.BuildingID, Rooms.RoomID, RoomName, MaxCapacity, MinCapacity, RoomOpening, RoomClosing, BuildingName, Photo1 FROM Rooms, Buildings, RoomPhotos
    WHERE Rooms.RoomID NOT IN
    (
        SELECT DISTINCT RoomID FROM RoomBooking 
        WHERE BookingDate = @BookingDate
        AND ( 
            (BookingStart BETWEEN @BookingStart AND @BookingEnd)
            OR (BookingEnd BETWEEN @BookingStart AND @BookingEnd)
            OR (BookingStart <= @BookingStart AND BookingEnd >= @BookingEnd)
            )
    )
    AND
    RoomOpening <=@RoomOpening
    AND
    RoomClosing >= @RoomClosing
    AND
    (SELECT max(Capacity)as MaxCapacity FROM RoomLayouts where RoomLayouts.RoomID=Rooms.RoomID) >=@Attendees
    AND
    MinCapacity <=@Attendees
    AND
    Rooms.BuildingID = Buildings.BuildingID
    AND
    Rooms.RoomID = RoomPhotos.RoomID
    AND
    Buildings.SiteID = @SiteID
    
    AND Rooms.CateringAvailable = @IsCatering

Code (markup):

Where it says AND Rooms.CateringAvailable = @IsCatering I only want this to happen if the value of @IsCatering is True....

Something like

if @IsCatering is 'True' then

AND Rooms.CateringAvailable = True

Else
'Just forget this statement
End if

 

You define @IsCatering as a varchar(50). Do you need to make sure it is not null, or do you need the change the type of @IsCatering?

 

@IsCatering comes into the SP as a string with a value of True or False.....Thats fine I just need it to do 'AND Rooms.CateringAvailable = True' ONLY if the value @IsCatering = true