>Hi,
>
>Do I understand correctly that if there is an error (typo or undeclared variable or whatever problem) within TRY/CATCH, the global ON ERROR DO MyErrorHandler() will catch it? That is, that TRY/CATCH is not "isolated" from the global error handling.
>Please let me know if I am correct. Or, if I don't understand it correctly.
>
>TIA.

You understood it wrong. A Try/Catch isolates the error from outside block (silences the error if you do nothing in CATCH). You can make the error available to outside block by using THROW in catch. ie:

On Error Do errHandler
Try
	? "A"+15
Catch To oErr
	*	m.oErr.UserValue = "Error caught with catch."
	Throw
*	Throw "Error caught with catch."  && This is not the same thing
Endtry
? m.newVar
On Error

Procedure errHandler
	? "Error: [["+Message()+"]]"
Endproc

PS: Personally I prefer using On Error. Try Catch is not as powerful IMHO, doesn't catch every error that ON ERROR catches for example.