Input textboxes can have the following four validation rules added to them:
If a validation rule is added to a control, the action Validate Controls on Screen can be used to check if the object obeys these rules.
If the input for the control breaks a rule, this action will highlight the field in red, display what needs to be fixed, and all other actions below this action will be ignored.
Example: Below, the Name field is required and the action was called to validate this field. Since the field was empty, it was outlined in red and text is displayed to show what the validation error was. Any other action after this action is ignored.
When you add the validate controls on screen action, you can choose to validate: