When designing your Send Message or Start iSMS elements, you can control the content that is displayed based on the evaluation of a condition. This behavior is implemented by the SMS Web If widget.
The "then" and "else" parts
At development time, this widget is presented as a table where the first line contains the content displayed if the condition is true, corresponding to the "then" part; and the second line contains the content displayed if the condition is false, corresponding to the "else" part. Both these contents are optional, i.e. you can specify only the "then" or "else" part of the widget.
In the "then" and "else" parts you can type text and use the SMS widgets, just like in the rest of your screen.
At runtime, the condition is evaluated and only one of the alternate parts is displayed to the end-user.
You can have nested SMS If widgets to, for example, implement a switch control statement at the screen flow.
SMS If Widget Properties