I create a new tab in sales order head information called addational data .and i put a component named 'add_address' . My problem is when I click the save button. the 'add_address' will be saved default value when it is initial. otherwise, it will be saved with input value.
Now what I do is :
Form userexit_save_document.
if xvbak-zz_address is initial.
xvbak-zz_address = 'defalut address'.
endif.
endform
but it didn't work...
anyone can help me?