Hi, MB,
A dropdown isn't a command, it's a widget in a dialog -- a rectangle
containing text or a picture, with a button to its right that has a
downward-pointing arrow. When you click the arrow, a list "drops down" from
the rectangle so you can pick a different value.
In the next paragraph, I'll talk about what I see in Word 2000, but I think
it's the same in Word 97. Someone will correct me if I'm wrong.
In the Format Text Box dialog, the second section from the top is labeled
"Line". Within that section, the first item is labeled "Color" and the
rectangle is filled with black at first. When you click the arrow button
next to it, a mini-dialog appears with a bunch of colors -- but the very top
thing there is a rectangle that says "No Line". Click that. The mini-dialog
disappears, and the Color rectangle now says "No Line". Click the OK button.
The text box will now show a non-printing border as long as it's selected,
but the border will disappear when the cursor is elsewhere on the page.
The difference between "No Line" and a white border is that a white border
will be visible in a printed document if you place the text box over some
colored background such as a picture. A "No Line" border will always be
invisible.