// To validate the grid, flexlayout and the custom field configuration layout

        public void OnButtonClickedValidate(object sender, EventArgs args)
        {
            foreach (View item in ((StackLayout)this.Content).Children)
            {
                if (item.GetType() == typeof(EntryField))
                {
                    EntryField E = (EntryField)item;
                    E.Validate();
                }
            }

            foreach (View item in formGrid.Children)
            {
                if (item.GetType() == typeof(EntryField))
                {
                    EntryField E = (EntryField)item;
                    E.Validate();
                }
                if (item.GetType() == typeof(PickerField))
                {
                    PickerField P = (PickerField)item;
                    P.Validate();
                }
            }

            foreach (View item in formStack.Children)
            {
                if (item.GetType() == typeof(EntryField))
                {
                    EntryField E = (EntryField)item;
                    E.Validate();
                }
                if (item.GetType() == typeof(PickerField))
                {
                    PickerField P = (PickerField)item;
                    P.Validate();
                }
            }
        }