Problem in passing parameter

I don't know why the following code always have "P_ACCOUNTGL" is not an internal table." error message. I've already defined P_ACCOUNTGL as type of table. thanks

data: ls_documentheader TYPE bapiache08,

lt_accountgl like table of bapiacgl08 with header line.

PERFORM create_gl_doc USING ls_documentheader

lt_accountgl

form create_gl_doc using p_documentheader

p_accountgl

p_currencyamount.

CALL FUNCTION 'BAPI_ACC_GL_POSTING_POST'

EXPORTING

documentheader = p_documentheader

IMPORTING

obj_type = lv_obj_type

obj_key = lv_obj_key

obj_sys = lv_obj_sys

TABLES

accountgl = p_accountgl

currencyamount = p_currencyamount

return = lt_return

extension1 = lt_extension1

EXCEPTIONS

others = 1.

endform.