The moveWindow message is sent to the current card whenever the location of
any stack window changes. MoveWindow is a system message, so it serves only
to notify that an event has happened, not that it is going to happen if the
message reaches HyperCard.
Scripters can use a moveWindow handler to figure out how to reposition
other windows.
One way to prevent users from dragging windows is to hide the titlebar of
the card window. Use hide titlebar. Restore the titlebar later with show
titlebar. Note that any stack that opens in that same window will not have
a titlebar (so scripters want to restore the titlebar on closeStack and
suspendStack). The command will not affect other windows displaying stacks.
This article is adapted from the Claris Tech Info database.