how do i remove the "always" choice from my Droid for dropbox

[Android Question]

I accidentially hit the "always" button for selecting dropbox for attaching a picture for texting. Need to remove it so I can attach pics from my galaxy.

How do I accomplish this?

 

[kejlyCZ]

Settings / Applications, swipe to All (or Downloaded), find Drophox there, go little bit down and "Clear defaults" (or something similar to this)