"That does not work."

When the Player tries to do something that has no purpose for the game you will have to give him a proper reaction. For example the player tries to talk to a door. The script of the door obviously has no on (talk) Event.

In this case the game looks into the characters script for a Cant-Event. Click on your Character within the roomwindow and open his/her script. Add this to the script :

on (canttalk) speech (self ; I cannot talk with that.)

You can use cant with every one of your gamecommands. You can also create a standard reaction for any gamecommand by using on (cantall) . If there is no special on (cant...) event the game will look for (cantall) .