Help with plc college project

I am doing a project on a parking garage. It will hold 25 cars ,then a light will illuminate that says lot is full. Then when one car leaves lot light will go off. I have everything set up for light to come on, but when I get one car to leave the light will go off, but will come back on. My instructor told me that I needed to do a compare on count up and count down. I tried this but it is not working. I am sending an attachment for the diagram that I have used for project. This is for Allen-Bradley PLC. Any help would be greatly appreciated, as I new to all of this. Thanks!

I got it figured out!

Two thumbs up.

they have these in las vegas at the wynn, it counts how many cars are in the garage.

your project

used there same counter address

use there same counter address

send your emaiol id