Change variant in OO ALV after first dysplay

Hi,

I have a problem with an OO ALV. I need to chage the variant after it is show first time (ie. when a button is pushed).

I tried this, but it doesn't work:

DATA: lr_variant TYPE disvariant.

• Get actual variant

CALL METHOD gridc->get_variant

IMPORTING

es_variant = lr_variant.

...

• Set new variant

CALL METHOD gridc->set_variant

EXPORTING

i_save = 'A'

is_variant = lr_variant.

• Set new fieldcatalog

CALL METHOD gridc->set_frontend_fieldcatalog

EXPORTING

it_fieldcatalog = i_fcatc1[].

• Refresh ALV

CALL METHOD gridc->refresh_table_display.

What is the problem?

Thanks