run-time error while executing alv grid report

Hi everyone

I m trying to run a alv grid report it is giving a run time error while executing the statement CALL METHOD V_ALV->SET_TOOLBAR_INTERACTIVE.

Actually i added 2 buttons in the toolbar.after that when i execute the report i m getting errors.

<b>Error Analysis</b>

An exception occurred that is explained in detail below.

The exception, which is assigned to class 'CX_SY_REF_IS_INITIAL', was not

caught in

procedure "TOOLBAR_MENUS_INIT" "(METHOD)", nor was it propagated by a RAISING

clause.

Since the caller of the procedure could not have anticipated that the

exception would occur, the current program is terminated.

The reason for the exception is:

You attempted to use a 'NULL' object reference (points to 'nothing')

access a component (variable: "ME->M_CL_MENU_BUTTON_VARIANT").

An object reference must point to an object (an instance of a class)

before it can be used to access components.

Either the reference was never set or it was set to 'NULL' using the

CLEAR statement.