tabbar.cell Doesn't support "attachForm" attribute or method

I encounted a problem.
The codes and errors are in the attached figure.
while I used tabbar.cells(“a1”).attachToolbar, or attachStatusbar, both is ok.
But when I switched to attachForm, error occurs.
Thanks!


Solved.
related topic.
viewtopic.php?f=4&t=18957
the same problem.
But, it seems that many packages include dhtmlxcontainer.js.