Declaration of WA for Table Type

Hi,

I am trying to append a structure data to a table type.

For example:

I have a Table Type called ZTABLE_TYPE of Line Type ZSTRUCTURE.

In my program, my declaration is as below:

DATA itab TYPE STANDARD TABLE OF ZTABLE_TYPE.
DATA work_area TYPE ZSTRUCTURE.

work_area-field1 = 'abc'
work_area-field2 = '123'
APPEND work_area TO itab.

However, when I try to activate, I received a syntax error:

"WORK_AREA" cannot be converted to the line type of "ITAB".

Can I get some help on whether I have declared wrongly, or is there a more appropriate way to append data into a table type.

Thanks!