A question about PL/SQL

It seems some PL/SQL programs can only run once on a sqlplus seesion If I run the following program twice, I will get the message

DECLARE
*
Error at line 1
ORA-03113:end-of-file on communication channel

The system will then disconnect me from oracle. Can any one tell me what the problem is? Thanks  

/* the program does nothing */
DECLARE

	TYPE testtype IS TABLE OF INTEGER
		INDEX BY BINARY_INTEGER;
	X  testtype;
	FUNCTION HO (A testtype   ) RETURN testtype IS
	BEGIN
		RETURN A;
	END HO;
BEGIN
	X(1):=10;
	X(2):=20;
	X:=HO(X);

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|Raymond Ho-Yin Chow  | chow3_at_server.uwindsor.ca                           |


|Undergraduate Student| University of Windsor	                           |


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