5 Perform Actions in a Table or Form-over-Table Layout
In addition to data entry operations such as edit, create, and delete described previously, some web applications define special operations, "custom actions", on particular business objects. For example, an Invoice might define actions called "Approve" or "Reject" that can be performed on each invoice.
As a business user, you don't need to do anything special to use these actions in a data table. Click Download Data to download data to your table, then update an action's cell values much as you would any other field's cell value. In the following Table layout, rows marked as Close are those where the user has updated cell values corresponding to the Close Action (Close) and Close Reason (Close) action columns.
Description of the illustration custom_actions_table.png
When you add or update a value in an action cell first, the row is marked for that action in the Change column. Other cells in that row that don't involve actions are grayed out and cannot be edited. But if you add or update a value first in a cell that doesn't involve an action, the row is marked as an Update in the Change column and the action cells in that row are grayed out (as shown in the following image). In other words, the first action you perform on a row determines that row's pending action.
Description of the illustration custom_actions_table_automark.png
You can also mark rows for an action by selecting Mark for Action from the Table Row Changes menu. With this option, if only one action is defined, you'll be prompted to confirm. If more than one is defined, you'll be prompted to select from a list of available actions:
Description of the illustration custom_action_markforaction.png
When a row is marked for an action, the action's fields also receive the same validation, as described in Understanding Data Validation.
If you're working with a Form-over-Table layout, select Perform Action in the Form Changes menu, then follow the prompts to perform actions on a Form row, as shown here where you're prompted to select an action, then provide values for the action's fields: 
Description of the illustration fot_custom_action.png
An action can be performed only on an existing row (not on a pending Create row).
Once you perform an action on the form, it takes effect immediately, unlike an action in a table (where rows are marked for actions and the actions are performed later during an upload).
Also, form row data is not automatically refreshed after an action is performed, even if the action was successful. Click Download Data if you want to refresh data in the form row.