SQL & PL/SQL

Hi,

I am trying to generate report through XML publisher using pl/sql procedure. In my procedure i m using the function DBMS_XMLGEN.getxml to generate the output in XML format & storing it in a variable declared as CLOB type. The reports are running fine smaller result set but its giving error "Value or Numeric Error' for larger resul set. Following is the way i am using the function:

select DBMS_XMLGEN.GETXML('select * from dual') into result from dual;

Where result is declared as CLOB Type.
Can anyone help me? How to get the output for larger result set?
Waiting for Early Reply.......

Thanks
Spriha