I have a text box that I would like to populate based on a selection chosen
from a drop-down list.  If user chooses "Dallas" from a drop-down list box, I
want my text box field to populate with "John Doe."  I set up the rule on the
text box with condition "If dropdown is equal to Dallas" set field's (text
box) value to "John Doe."

However, when I preview the form and choose Dallas from my drop-down, the
text box does not populate.  What am I doing wrong?  Thanks!