Not sure if it has any specific message either, but you can try to find the text edit box (this isn't the most robust option but should work in simple cases)
Names Default To Here(1);
gb_ref = (Current Report() << XPath("//OutlineBox[@helpKey = 'Graph Builder']"))[1] << Get Scriptable Object;
cur_stretch = All(gb_ref << Get Auto Stretching);
fit_state = If(cur_stretch, "Off", "On");
gb_ref << Fit to Window(fit_state);
Report(gb_ref)[GraphBuilderTitleBox(2), TextEditBox(1)] << Set Text(Eval Insert("FTW = ^fit_state^"));
If you want to make sure that the subtitle is visible you can add
gb_ref << Show Subtitle(1);
to end
-Jarmo