Element is getting initial

Hello,

I am using  Table UI  element.  When i click on Select ALL option of the table  and click on button  , the element  of the node is getting initial after the statement 

lo_el_sample = lo_nd_nd_sample->get_element( ) method.

But where as when iam selecting all the records individually   the element is  not getting initial .  the problem is only with the Select All option of the table.

Please help.

Thanks .