Double Click on the Room field to bring up the Room Assignment box => click on the drop down to select the desired room number => click Post to assign the room:

For a more advanced shortcut, click on the three dots on the Room Assignment:

This will bring up a modified version of the Room Assignment Calendar (the full version of the Room Assignment Calendar is found under the operations Menu; best used when assigning multiple rooms) => the dates of the reservation will load automatically in the Date From and Date to => only the room type of the reservation will appear => to assign reservation to a room, click and drag the reservation from the bottom to the desired room number =>

Or as a second option => double click on the empty cell beside the desired Room Number and the "Assign reservation to room" box will appear => click Assign to complete:

Should you choose the wrong room, double click on the Res Id of the Reservation you just assigned and the Release Room box will appear:

**Please Note: you can only un-assign the reservation you are currently working in.  For full capabilities or assigning multiple rooms, use the full Room Assignment Calender found under the Operations menu**

Upon releasing the reservation from the room, it will appear down at the bottom to be re-assigned: