Catch problem

[s007amf(at)news.wright.edu (ALAN FRAZIER)]

Recently, I started learning the catch procedure to help with some error 
checking.  I typed the code word-for-word out of the IDL 5.3 
documentation:

PRO ABC

	A = fltarr(10)
	
	CATCH, Error_status
	
	IF Error_status NE O THEN BEGIN
		PRINT, 'ERROR INDEX: ', Error_Status
		PRINT, 'ERROR MESSAGE: ', !ERR_STRING
		A = FLTARR(12)
		ENDIF
			
	A[11] = 12
	
	HELP, A

END

to help me learn this command.  However, this code does not seem to 
execute correctly.  As far as I can tell, the code causes some sort of 
infinite loop on the if statement.  Any ideas what I am doing wrong?  I am 
using IDL 5.4 on a Mac.

--
Alan