Oracle PLSQL: Ceasing Password Program

CREATE OR REPLACE FUNCTION REPP(CHECK_PASS VARCHAR2) 
RETURN VARCHAR2 IS
STRA VARCHAR2(200);
STRE VARCHAR2(200);
BEGIN
 IF ASCII(CHECK_PASS) BETWEEN 65 AND 90 THEN
 STRA:= REPLACE(CHECK_PASS,CHECK_PASS,'**************************');
RETURN(STRA);
ELSE
STRE:=REPLACE(CHECK_PASS,'abcdefghijklmnopqrstuvwxyz','$');
RETURN(STRE);
END IF;
END;