* Builds the Insert Image form.
*/
@Override
protected void buildForm() {
content.setWidth("500px");
image = new FileBox();
centerHorizontal = new CheckBox("Center horizontal");
centerHorizontal.setValue(true);
insertAsFloat = new CheckBox("Insert as float");
insertAsFloat.setValue(true);
insertAsFloat.addValueChangeHandler(new ValueChangeHandler<Boolean>() {