(139,13): BCE0005: Unknown identifier: 'GetGUIManager'

I trying to use buttons to switch scenes I have a total of four errors.Same errors but different lines :

(139,13): BCE0005: Unknown identifier: 'GetGUIManager'.

(153,16): BCE0005: Unknown identifier: 'senderObject'.

(168,16): BCE0005: Unknown identifier: 'senderObject'.

(169,17): BCE0005: Unknown identifier: 'senderObject'.

Here is my code :

 #pragma strict
 
 import UnityEngine.SceneManagement;
 
 @script AddComponentMenu ("EGUI/UI_Elements/Button")
 
 // public class EGUI_Button extends EGUI_Element {}
 
 // List of built-in functionality types
 public enum ButtonAction
 {
     None,                   // Do nothing
     Custom,                 // Call function (name in callFunction) with parameter for actionRecipient object (this gameObject is default)
     LoadLevel,              // Load level with index/name in parameter
     RestartLevel,           // Restart current level
     ExitGame,               // Close application
     SetQuality,             // Set quality level according to parameter (Fastest, Fast, ... Fantastic)
     DecQuality,             // Decrease quality level 
     IncQuality,             // Increase quality level  
     SetResolution,          // Set screen resolution according to parameter (1024x768, 1920x1080 ... etc)
     OpenURL,                // Open URL specified in parameter
     CloseEverything,        // Close/disable whole GUI manager and all related GUI-elements. 
     Resume,                 // Close parent GUI-element and set time-scale to 1
     ShowAnother,            // Show GUI-element specified in actionRecipient
     ShowPrevious,           // Show previous GUI-element
     HideThis,               // Hide parent GUI-element  
     HideThis_ShowAnother,   // Hide parent GUI-element and show window specified in actionRecipient
     HideThis_ShowPrevious,  // Hide parent GUI-element and show previous window
     SoundSwitch,            // Enable/Disable all sounds in the scene
     LoadPreviousLevel,      // Load the previous level if there is one else load load the current one
 };
 
 var onClickAction: ButtonAction;    // Action preset to perform onClick
 var actionRecipient: GameObject;    // Optional link to action recipient object
 var callFunction: String;           // Optional name of custom function to call
 var parameter: String;              // Optional parameter to send/use in the Action
 
 //=====================================================================================================
 // Overload parent OnClick function to Perform built-in actions
 function OnClick () 
 {
     //     super.OnClick();
     PerformAction ();
 }
 
 //----------------------------------------------------------------------------------------------------
 // Perform built-in actions according to selected type (onClickAction)
 function PerformAction () 
 {
     switch (onClickAction)
     {
         case ButtonAction.None:
             break;
 
         case ButtonAction.Custom:
             if(!actionRecipient)
                 actionRecipient = gameObject;
             if(parameter.Length > 0)
                 actionRecipient.SendMessage (callFunction, parameter, SendMessageOptions.DontRequireReceiver);
             else
                 actionRecipient.SendMessage (callFunction, SendMessageOptions.DontRequireReceiver);
             break;
 
         case ButtonAction.LoadLevel:
             Time.timeScale = 1;
             try
                 SceneManager.LoadScene(int.Parse(parameter));
             catch(error)
                 SceneManager.LoadScene(parameter);
             break;
 
         case ButtonAction.RestartLevel: 
             Time.timeScale = 1;
             SceneManager.LoadScene(SceneManager.GetActiveScene().name);
             break;
 
         case ButtonAction.LoadPreviousLevel: 
             Time.timeScale = 1;
             if (SceneManager.GetActiveScene().buildIndex > 0) // if not the first scene load the prvious scene
                 SceneManager.LoadScene(SceneManager.GetActiveScene().buildIndex - 1);
             else
                 SceneManager.LoadScene(0);
             break;
   //changed here
         case ButtonAction.ExitGame: 
             Application.Quit();
             break; 
 
         case ButtonAction.SetQuality: 
             switch (parameter)
             {
                 case "Fastest":
                 QualitySettings.SetQualityLevel(QualityLevel.Fastest);
                 break;
 
                 case "Fast":
                 QualitySettings.SetQualityLevel(QualityLevel.Fast);
                 break;
 
                 case "Simple":
                 QualitySettings.SetQualityLevel(QualityLevel.Simple);
                 break;
 
                 case "Good":
                 QualitySettings.SetQualityLevel(QualityLevel.Good);
                 break;
 
 
                 case "Beautiful":
                 QualitySettings.SetQualityLevel(QualityLevel.Beautiful);
                 break;
 
 
                 case "Fantastic":
                 QualitySettings.SetQualityLevel(QualityLevel.Fantastic);
                 break;
             }
             break;  
 
         case ButtonAction.IncQuality: 
             QualitySettings.IncreaseLevel();
             break; 
 
         case ButtonAction.DecQuality: 
             QualitySettings.DecreaseLevel();
             break; 
 
         case ButtonAction.SetResolution: 
             Screen.SetResolution ( int.Parse(parameter.Substring(0,parameter.IndexOf("x"))),  int.Parse(parameter.Substring(parameter.IndexOf("x")+1)), Screen.fullScreen);
             break;
 
         case ButtonAction.OpenURL: 
             Application.OpenURL(parameter);
             break;               
 
         case ButtonAction.CloseEverything: 
             GetGUIManager().gameObject.SetActive(false);
             break;                                                                                                                                                                                                                                                                      
 
         case ButtonAction.Resume: 
             Time.timeScale = 1;
             transform.parent.gameObject.SendMessage("Disable");
             break; 
 
         case ButtonAction.ShowAnother:
             if(actionRecipient)
                 actionRecipient.GetComponent(EGUI_Element).SetActivation(true, transform.parent.gameObject);
             break; 
 
         case ButtonAction.ShowPrevious:
             if(senderObject)
                 senderObject.SetActive(true);
             break; 
 
         case ButtonAction.HideThis:
             transform.parent.gameObject.SendMessage("Disable");
             break; 
 
         case ButtonAction.HideThis_ShowAnother:
             if(actionRecipient)
                 actionRecipient.GetComponent(EGUI_Element).SetActivation(true, transform.parent.gameObject);
             transform.parent.gameObject.SendMessage("Disable");
             break; 
 
         case ButtonAction.HideThis_ShowPrevious:
             if(senderObject)
                 senderObject.SetActive(true);
             transform.parent.gameObject.SendMessage("Disable");
             break; 
 
         case ButtonAction.SoundSwitch:
             if(actionRecipient)
                 actionRecipient.GetComponent(AudioListener).enabled = !actionRecipient.GetComponent(AudioListener).enabled;
             break; 
     }
 }