How can I determine if a help dialog box is open, and then close it if it is open

This dialog box is opened by a function in a class object. If a class object function hangs up, the dialog box is left open. The dialog box is created by the following obj.info = op_status(obj.info,'Running');

op_status function is: function rc = op_status(fh,str) fh =helpdlg(str, 'Tester Status'); set(fh,'Position',[10 260 160 60],'MenuBar','none'); rc = fh; end

I can close the dialog box by issuing the simple command close(obj.info).
But, if the box is already closed, I get this error message:
??? Error using ==> close at 93
Invalid figure handle.

I want to include this within a script or function to reset figures and listeners, etc. when something hangs up.

I tried findobj to detect the help dialog box, but it does not seem to detect it.

Answer 1

[Paulo Silva]

try
close(obj.info)
catch
end

[Paulo Silva]

Elaine you accepted my answer but the other answers are better, please select other answer or I will delete this one, thanks

Answer 2

[Matt Fig]

For future reference, FINDOBJ won't return the handle to objects which have handlevisibility set to off. Use FINDALL instead. In particular,

helpdlg('Help string','Help Dialog')
findall(0,'tag','Msgbox_Help Dialog') % Notice how Tag was made.

Answer 3

[Jan]

if ishandle(obj.info)
  delete(obj.info)
end

[Elaine]

This solution also worked!