... =keepform_listbox.Color; // alert_colour[5 ]; // ice-blue or white. with keepform_listbox do ItemHeight:=Round(Canvas.TextHeight('')*8 /7 ); // owner-draw listbox, 8/7 arbitrary.+ if Assigned(data_child_form) and (data_child_form.Visible=True) then+ keep_form.read_info_buttonClick(data_child_form); end; Hi Graeme, Many thanks for that. Unfortunately it is a bit more complicated, because the same form is used as a child elsewhere, like this: 2_050938_010000000.png Which means it may have been set Visible there, and simply testing Visible doesn't prove that it is showing on the trackpad. On a small screen showing it when the user didn't request it could be annoying. (I can't remember why I did that, and it's causing problems in Lazarus. It might be better to duplicate the form and use a different one in each place where it is needed.) So the obvious condition becomes: if (data_child_form.Visible=True) and (data_child_form.Parent=pad_form) which would work ...