Field Symbol

Hi all

Im using the follow code in a user exit to retrieve the text typed for a certain item of the transacatio ME51N.

.

.

field-symbols <ztext> type any " or

field-symbols <ztext2> type standard table.

assign ('(SAPLMMTE)gt_control') to <ztext>.

Even If I have data stored in the gt_control, When I check sy-subrc, I get sy-subrc <> 0 .

One of the field of this gt_control is a structure type mmpur_textlines where is in fact the data I need to test.

Something like: <ztext>-textlines-tdline must be <> 0 .

Any idea how can I do this !?

Many thanks.

Cristina