how to get fields in form from bean

hello everyone,

I am having a bean from which I am getting fields on form and all fields are put in grid layout.
But I want to do that some fields in different grid layout and then all these layout in a single vertical layout.

this is the code that i am using in form right now
public void setItemDataSource(Item newDataSource) {
if (newDataSource != null) {
newTradeshowMode = false;
List<Object> orderedProperties = Arrays.asList(TradeshowContainer.NATURAL_COL_ORDER);


super.setItemDataSource(newDataSource, orderedProperties);

v1.addComponent(h1);
v1.addComponent(h2);
v1.addComponent(h3);
h1.addComponent(getField("show_ref"));
h1.addComponent(getField("show_name"));
h1.addComponent(getField("show_retail"));
h2.addComponent(getField("prod_category_id"));
h2.addComponent(getField("is_active"));
h2.addComponent(getField("currency"));
h3.addComponent(getField("show_master_id"));
h3.addComponent(getField("start_dt"));
h3.addComponent(getField("end_dt"));
setReadOnly(true);
getFooter().setVisible(true);
currentRecord = newDataSource;
} else {
super.setItemDataSource(null);
getFooter().setVisible(false);
}

}

and this is the code that is using for displaying form

VerticalLayout vert = new VerticalLayout();
setFirstComponent(tradeshowList);
VerticalLayout v2 = new VerticalLayout();
GridLayout layout = new GridLayout(4,1);
layout.setSpacing(true);
layout.setSpacing(true);
tradeshowForm.setLayout(layout);
layout.setMargin(true, false, false, true);
tradeshowForm.setStyleName("detailForm");
Panel formPanel = new Panel("Tradeshow Details");
formPanel.setStyleName("formPanel");
formPanel.setHeight("95%");
formPanel.setWidth("70%");
vert.addComponent(tradeshowForm);
formPanel.setContent(vert);
//setSecondComponent(formPanel);
setSplitPosition(1000, SplitPanel.UNITS_PIXELS);
}
}

Plz help me..
Vikas