TB_ISBUTTONINDETERMINATE  .214G_ 

The TB_ISBUTTONINDETERMINATE message determines whether the specified button in a toolbar is indeterminate.

TB_ISBUTTONINDETERMINATE

wParam = (WPARAM) idButton;

lParam = 0;

Parameters

idButton

Command identifier of the button.

Return Values

Returns nonzero if the button is indeterminate or zero otherwise.