you may only read from table..Error

HI Experts ,

I've the following issue.

I've created a FM in which it_char is import parameter

data : it_char type ztest

where ztest is table type .

now the issue is that when I run code inspector I get an error has bellow when I do this,

SORT it_char by atnam.

READ TABLE it_char INTO lv_chara WITH KEY atnam = lwa_allocvaluesnum-charact .

ERROR is

you may only read from table "it_char".

now how can I remove this error ???

Regards,

Suhas