Field symbol not assigning?

Hi everyone,

I am trying to assign a value to a field symbol as follows:

LOOP AT gtab_out REFERENCE INTO gr_tab_out.

         ASSIGN COMPONENT l_fieldname OF STRUCTURE gr_tab_out TO <lfs_fieldname>.

l_fieldname contains a column name of gtab_out and it is populated correctly. But, for some reason, the field symbol <lfs_fieldname> is not being assigned.

What could be the problem here?

Thanks,

Shkelqim