To
configure validation at a list or library level, open the list or
library settings page by switching to the List ribbon or Library ribbon
and clicking the List Settings or Library Settings button. In the list
or library settings page, click the Validation Settings link to open
the validation settings page shown in Figure 1.
Here you can define a
formula that will be evaluated when the user tries to save a new item
in the list or library. The formula must evaluate to TRUE for the save to be successful.
For example, if you have two
date fields, select the Due Date column from the Insert Column box on
the right and click the Add to Formula link to add it to the box, and
then do the same with the Starting Time column. In this way, you add
the column names (surrounded by square brackets) to the formula. Add a
> (greater than) sign between them, as shown in Figure 1, and click Save.
Another option in this page is to set the message the user sees if the formula fails to evaluate to TRUE. For example, Figure 1 is set to display a message to the users that the Due Date must be after the Starting Time.
You can use AND and OR
operators to chain validation conditions in the formula. For example,
you can have the formula check that either the State/Province column or
the Country/Region column has a value and that either Home Phone or
Mobile Phone has a value, as shown in Figure 2.
