00:00This is how you create a real-time check-in and check-out list.
00:03Before we start, let's look at a countif function here.
00:06We're going to say equal countif and the first argument we're going to put in as
00:10the column in check-in, comma, and the criteria would be the student list
00:16like this and close parenthesis hit enter. You'll get a series of zero here.
00:20Now if you were to type here the existing student name, you can see that
00:24you do get a value of one if the name exists in your student list.
00:28But if you were to put a name that does not exist, you'll get a zero here.
00:34Now we can use this countif function if we encapsulate this with the filter function
00:39and the first argument on the filter function will be the student name, comma,
00:43and the second argument which is your criteria or include will be less than one
00:48to indicate that the name already exists. You'll get a series of names which is
00:53already in check-in. Now to seal the deal, what you have to do is to select the
00:57check-in and let's create a pull-down menu here. Go data, data validation.
01:03In here, you're going to be on the setting tabs, select list, and on the source
01:08you're going to click this button and basically select all the names in your
01:12checkout list. But make sure you remove the last section of the cell and put a
01:17pound to allow dynamic growth of the name. And now you press enter twice and now you
01:21have a pull-down menu. Now every time if you were to check out any names, you can see
01:26that the checkout name or the checkout list get updated.
01:33And if you were to remove any name from the check-in, it get inserted back into the
01:37checkout list.
