Compare two int columns in a Sharepoint list

Question

I´m doing a course catalog app for SharePoint. And I have a list called Courses. In that list I have two columns called: Seats and FreeSeats.

When you make a new course the boss decide how many can apply to the course.

So for ex: 5 seats.

When the Fifth person apply there most be a stop.

So I thought if I have the column FreeSeats, it can count up every-time someone apply. And when it is the same as the column Seats it will NOT be able to apply.

So I guess I need some sort of count that add 1 every-time someone apply to the FreeSeat column. And in a if loop check if the value of FreeSeats are smaller than Seats, you can apply. If its bigger than Seats it will come a stop message.

Someone have any idea how a code like this looks like? I have never done this before.

Answer 1

Search for: limit items newform or something like that

Basically you have to

• add a hidden listview to the newform which displays all registered seats

You can then use javascript code to hide the whole form when the maximun is reached

The example somwhere here on SO uses a calculated column

You could also at a content editor webpart which checks ctx.ListData.row.length