TYPE STANDARD TABLE OF in a Formroutine

Good afternoon dear ABAP colleagues,

I am having a problem while passing an internal table as changing parameter in a Form Routine.

The problem is: I have a Form like this:

FORM get_postings USING        p_doc          TYPE z_doc

                             CHANGING ct_doclines TYPE STANDARD TABLE OF z_doclines

.....

ENDFORM

I declared ct_doclines like TYPE STANDARD TABLE OF because the internal table which I am going to pass in the call is declared like this:

lt_doclines TYPE STANDARD TABLE OF z_doclines.

In the call, I write:

PERFORM get_postings USING <ls_doc>-doc

                                     CHANGING lt_doclines

I always get the error message while activating: Difference with parameters. Formal parameters: 4, current parameters: 2

And I do not know to fix it. I tried several things. Without putting the table as changing there is no problem, but once I add it, it always comes the same compilation error.

Does anybody have any hint?

Thanks a lot!

Jorge.