Enabling and Disable textbox control and setting text to empty on dropdown change

So I'm assuming you've created a View that has a dropdown and texbox control on it already, and the dropdown is populated with some values to choose from. So what you'd do next is add a rule on the dropdown that fires when it is CHANGED. In that rule, you'd add a Data Transfer rule where you'd place a checkbox next to your text box control but not enter a value in the field next to it. That would blank it out.