Using a button to prompt for a password

I have a form that is protected with a password so that the field data cannot be entered/modified unless the password is entered. I want to make it easier for the user to enter the password, so I created a button that will prompt for the password, and found a post elsewhere on this site that dealt with a similar issue.

Using the code sample from that post, I opened up the javascript editor and entered the following:
var pWd = app.response("Please enter Password","Document Control Only")

Then I tested that piece by going to the preview mode and clicking on the button. The problem is that nothing happens. The button depresses, but nothing happens, no prompt.

I notice that in the button properties there are three control types: Regular, Execute and Submit. I'm not clear on what the difference is betwwn Regular and Execute, and the default seems to be Regular. Thinking it might need to be on Execute, but when I change to Execute and save, it goes back to Regular.

What am I doing wrong? Any assistance would be greatly appreciated.