NativeSelect addItem doesn't work

I have
NativeSelect
on my
Panel
. The problem is I can’t add item to it.

       	NativeSelect addrselect = new NativeSelect("Address");
            
            addrselect.addItem("Frankfurt");
            addrselect.addItem("Penza");

        	addrselect.setWidth("64px");
        	addrselect.setHeight("64px");
        	addrselect.setCaption("Addresses:");
        	addrselect.setNullSelectionAllowed(false);
        	addrselect.setValue("Berlin");
        	addrselect.setImmediate(true);

Framework is
Vaadin 6.7.4
.

How I can fix it ?