private void okButton(){
		try {			
                    String CR = txtCR.getText();                    
                    if(CR.matches("[0-9]+")){
                        if(Sim.getNode(NodeName) instanceof NetworkLayerDevice){
                            NetworkLayerDevice tmpNode = (NetworkLayerDevice)Sim.getNode(NodeName);
                            tmpNode.getConfig().executeCommand("int " + NodeInt + " clock-rate " + CR);                            

                            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");
                        }else{
                            ((core.SerialNetworkInterface)Sim.getNode(NodeName).getNIC(NodeInt)).setClockRate(Integer.valueOf(CR));
                            Sim.getNode(NodeName).getNIC(NodeInt).DOWN();
                            if(chkUP.isSelected()){
                                Sim.getNode(NodeName).getNIC(NodeInt).UP();
                            }
                        }
                        
                        this.dispose();
                    }else{
                        lblError.setText("Invalid MAC Address!");
                        lblError.setForeground(Color.RED);
                        lblError.setVisible(true);
                        controller.shakeDiaLog(this);
                    }
		} catch (Exception e) {
			e.printStackTrace();
		}
	}