Assigning an Identifier
With the Assignment action you can include a simple scalar assignment in the list of actions of a button or menu item. The assignment has the format x:=y, where x is a scalar identifier and y is a scalar value or another scalar identifier.
To add an assignment action to your object:
While in Edit Mode, open the Properties dialog box of the Object you wish to specify the assignment for.
Change to the Action tab.
Select the Assignment action from the Select Action to Add list.
The Assignment dialog box appears on the right hand side of the tab
Specify the identifier you want to assign the value to in the Identifier box.
Enter a value or select an identifier that you want to use to assign the value in the Assign Value box.
Click Ok.