Message: About to lose Undo information
Cause
You have changed the maximum size of the undo information buffer. If you continue, you will lose all your undo steps.
What Can I Do?
 To 
 discard the existing Undo information click the Resize 
 button.
 To 
 discard the existing Undo information click the Resize 
 button. 
 To make the Undo information 
 buffer larger and hence preserve the existing Undo information, click 
 Don't Resize and enter a higher 
 value.
 To make the Undo information 
 buffer larger and hence preserve the existing Undo information, click 
 Don't Resize and enter a higher 
 value.