DropDown List in ALV

Hi,

i set a dropdown cell editor to alv but i didn't set the values of dropdown list.

i created a node that in node of alv for values of my dropdown list and filled that node.

lr_column = lr_config->IF_SALV_WD_COLUMN_SETTINGS~GET_COLUMN(
'PK08').

CREATE OBJECT lr_dropdownbyidx
  EXPORTING
    selected_key_fieldname = 'PK08'
    .
CALL METHOD lr_dropdownbyidx->set_valueset_fieldname
  EXPORTING
    value  = 'PK08T'
    .

lr_column->set_cell_editor( lr_dropdownbyidx ).

PK08 is an attribute in node of alv. PK08T is a node in node of alv.

i tried to fill values of dropdown list with this method but i got a dump that ;

Field symbol has not yet been assigned

has somebody know how to set values to dropdown list?

Can somebody help me pls?

Thanks.