private void okButton(){
		try {			
                    String SC = txtMAC.getText();
                    if(SC.matches("[0-9A-F][0-9A-F]:[0-9A-F][0-9A-F]:[0-9A-F][0-9A-F]:[0-9A-F][0-9A-F]:[0-9A-F][0-9A-F]:[0-9A-F][0-9A-F]")){
                        NetworkLayerDevice tmpNode = (NetworkLayerDevice)Sim.getNode(NodeName);
                        tmpNode.getConfig().executeCommand("int " + NodeInt + " mac-address " + SC);                            
                        
                        if(chkUP.isSelected()){                            
                            tmpNode.getConfig().executeCommand("int " + NodeInt + " shutdown");
                            tmpNode.getConfig().executeCommand("no int " + NodeInt + " shutdown");
                        }else{
                            tmpNode.getConfig().executeCommand("int " + NodeInt + " shutdown");
                        }
                        tmpNode.getConfig().executeCommand("write mem");
                        
                        this.dispose();
                    }else{
                        lblError.setText("Invalid MAC Address!");
                        lblError.setForeground(Color.RED);
                        lblError.setVisible(true);
                        controller.shakeDiaLog(this);
                    }
		} catch (Exception e) {
			e.printStackTrace();
		}
	}