How to use lexical parameter in XML Publisher report? Ending up with errors..

Hello All,

Actually there is a requirement to pass multiple values (Separated by comma or any other delimiter) to single parameter in an XML Publisher report.

So i am doing it using lexical parameter.I am getting below errors;

Calling XDO Data Engine...

java.lang.NullPointerException

and

Calling XDO Data Engine...

--SQLException

java.sql.SQLSyntaxErrorException: ORA-00920: invalid relational operator.

Please see my package;

CREATE OR REPLACE PACKAGE APPS.where_clause_pkg

IS

v_customer_type_where_clause VARCHAR2(4000);

FUNCTION customer_type_where_clause( p_customer_type IN varchar2)

RETURN BOOLEAN;

END where_clause_pkg;

/

CREATE OR REPLACE PACKAGE BODY APPS.where_clause_pkg