C# pausing the game during GUI keypad

Hello, I got this keypad script, which I wrote myself, and I was wondering if its possible to pause the movement of the camera while the GUI is up, and if I click on the GUI "Ok" button, the movement comes back as right now when Im trying to click the GUI buttons on my keypad. If you have played Splinter Cell Chaos Theory, like those keypads.

Keypad Code:

 public class Keypad : MonoBehaviour 
 {
     public string password = "1234";
     private string pwd = "";
     private bool Frodo;
     public AudioClip Ok;
     public GameObject objectToMove;
     // Use this for initialization
     void Start () 
     {
         Frodo = false;
     }
     void Update()
     {
         if (Input.anyKeyDown) { return; }
     }
     void OnTriggerEnter()
     {  
             Frodo = true;    
     }
     void OnGUI()
     {
         GUI.color = Color.blue;
         if (Frodo == true)
         {
             GUI.Box(new Rect(275, 50, 350, 250), "");//bakgrundsfält till knapparna
 
             pwd = GUI.PasswordField(new Rect(325, 60, 200, 50), pwd, "*"[0], 4);//4 siffrigt lösenord fält.
 
             if(GUI.Button(new Rect(350, 125, 50, 50), "1"))
             {
                 pwd += "1";
                 audio.Play();
             }
             if(GUI.Button(new Rect(400, 125, 50, 50), "2"))
             {
                 pwd += "2";
                 audio.Play();
             }
             if(GUI.Button(new Rect(450, 125, 50, 50), "3"))
             {
                 pwd += "3";
                 audio.Play();
             }
             if(GUI.Button(new Rect(350, 175, 50, 50), "4"))
             {
                 pwd += "4";
                 audio.Play();
             }
             if(GUI.Button(new Rect(400, 175, 50, 50), "5"))
             {
                 pwd += "5";
                 audio.Play();
             }
             if(GUI.Button(new Rect(450, 175, 50, 50), "6"))
             {
                 pwd += "6";
                 audio.Play();
             }
             if(GUI.Button(new Rect(350, 225, 50, 50), "7"))
             {
                 pwd += "7";
                 audio.Play();
             }
             if(GUI.Button(new Rect(400, 225, 50, 50), "8"))
             {
                 pwd += "8";
                 audio.Play();
             }
             if(GUI.Button(new Rect(450, 225, 50, 50), "9"))
             {
                 pwd += "9";
                 audio.Play();
             }
             if(GUI.Button(new Rect(500, 125, 65, 45), "Clear"))//rensar passwordfältet
             {
                 audio.Play();
                 pwd = "";
             }
             if(GUI.Button(new Rect(500, 190, 85, 85), "Ok"))//Ok knapp som man klickar på efter koden
             {
                 audio.Play();
                 if (pwd == password) 
                 {
                     audio.PlayOneShot(Ok);
                     objectToMove.transform.position = new Vector3(-75, 6, -18);
 
                 }
             }
         }
     }
     void OnTriggerExit()
     {
         Frodo = false;
     }
 }

Thanks in advance.