Hello Smitha,
While I don't offhand know how to implement such a feature, I can share two things I'd do to try to figure it out:
1. Read
Sun's Java Tutorial on Drag and Drop
2. Search this forum for past conversations on this topic (the search page link is at the top right page of this page).
Good Luck.
[ April 22, 2002: Message edited by: Dirk Schreckmann ]