c# - Docking guide when control added to another form -

i have windows form application , pass control of additional form main form's tabpage:

form2 frm2 = new form2(); frm2.toplevel = false; tppage1.controls.add(frm2); 

my question be: how can docking guide work? don't want use user control, because keep opportunity release control tabpage.

thank you,

daniel

update:

i use docking guide when move inner form, when it's control added main form. after startup app looks like: default layout

then add control of smaller form tabpage of main form: control added

i have docking guide when smaller form got docked, in case of picture above.

docking guide: (sorry, due lack of reputation) [https://]picasaweb[dot]google[dot]com/lh/photo/pgk8vqacihwk292th8mzjerqtyanis0mvioxq6axe9c?feat=directlink docking guide example popup block when move solution explorer in visual studio.

i realized docking guide works if use user control instead of forms, keep ability release control main form.

thank in advance,

daniel