Determine Modal Dialogbox is already open or not in MFC Application.

Hi All,

  I have created a MFC application, In which I have one window A, When I click on Window A button, new modeless dialog B isopening and Dialog B is containing a list items.
 When we click on 1st list item of dialog B it is launching new modal dialogbox C(It is modal for Window A). but still we canaccess Modeless dialog B. 
 Now when we click again on Modeless dialog B item, I wanted to know that How can we determine Modal dialogbox is already open or not ?. 

 As per my requirement if Modal dialog box C is already open i have to perform some action.

 Please let me know if anyone have thought.

Thank you,

dabara