LiveCycle Designer ES provides the capability to create customized conditional breaks for repeating subform objects. As opposed to paginating in response to data overflow, conditional breaks allow you to manually control how a subform breaks in a form based on a series of checks called conditional statements.
Through the conditional statements, you can verify data for a field within a repeating subform against previous instances of that field. The repeating subform can then be broken in response to a change in the data supplied to the field.
For example, on a telephone bill, you could break a repeating subform in response to changes in the field that stores the date of each billing entry. The telephone bill could then be visually broken down by date, making it easier for a user to read.
In addition to specifying a breaking condition, you can also specify a leading or trailing subform and indicate where to place the next instance of the repeating subform in the form.
6.
Click Insert Sample Expression Livecycle button insert expression To control subform and subform set breaks by using conditional statements and select the form design object within the subform to use as the comparison field for the conditional break. Alternatively, you can enter your own conditional statement in the field. To correctly evaluate as a conditional break, however, any user-defined conditional statements must evaluate to either true or false. Conditional statements that evaluate to true are executed.
After you create all of your conditional break entries, you should review the order in which they appear in the Edit Conditional Breaks dialog box. LiveCycle Designer ES processes the conditional breaks specified in the Edit Conditional Breaks dialog box in sequential order from top to bottom. Each conditional break for which the conditional statement evaluates to true is executed.
See also 

To control subform and subform set breaks by using conditional statements