I created a check in app based off a sharepoint list and I would like to assign the next available number after the user checks in. In the app the user clicks date and time and then a check in button and it updates the CheckInTime column in my sharepoint list. I have created another column called called CheckInTkt. What I want to happen is if the first user checks in at 1:00pm then I would like CheckTKT to update to 1 and then if another user checks in at 1:05pm then CheckItkt would update to 2. For the life of me, after hours of google searches and videos I can not figure out how to do this.