private void selectNode(){
		
		//Remove all items before regenerating the combobox.
		//This is because if a users selects the node twice, it would add the interfaces twice.
		cmbInterface.removeAllItems();
		
		NodeName = (String)cmbNodeName.getSelectedItem();
				
		try {
			Object nics[] = Sim.getNode(NodeName).getAllInterfaces();	//Get object array of interface names
			
			//Sort the array
			Arrays.sort(nics);
			
			for (int i = 0; i < nics.length; i++) { //Add them to the combobox
                            if(Sim.getNode(NodeName).isActiveInterface((String)nics[i]) )
                                cmbInterface.addItem(nics[i]);
			}			
			cmbInterface.setEnabled(true);
			
			DefaultGWAddress = ((core.NetworkLayerDevice)Sim.getNode(NodeName)).getDefaultGateway();
			if(DefaultGWAddress != null){
				txtDefaultGW.setText(DefaultGWAddress);
			}
			txtDefaultGW.setEnabled(true);
			
		} catch (Exception e) {	//This should never happen 
			e.printStackTrace();
		}
	}