To create and apply a conditional statement

From the Service Interfaces Editor, right-click an entry in the Mappings or Assignments pane and click Apply Condition from the popup menu.
In the New Name field, type a name for the condition, then click Create.
Build a condition using the fields and controls of the Condition Editor, then click OK.

Note:

To use an existing condition as a starting point for building a new condition, click an existing condition from the Existing Condition drop-down list and then proceed with step 2 above. This can be useful, for example, to negate an existing condition without having to recreate the existing condition as you define its negation.
Only conditions defined for the current operation appear in the Condition Editor as existing conditions.