What is the logic you are using to hide the control? For example, if your control were bound to field1 and you hid the control when field2 = true, you could then set a rule on field2 with the condition 'when field2 is true' to run the action to set the value of field1 to blank.... does that make sense? I've attached a quick sample in the header. Right click the link and select Save As, then right click the saved copy and select design to open in design mode. Preview to test functionality....