key word void cannot be used in this context

using UnityEngine; using System.Collections;

public class PlayerIO : MonoBehaviour {

 RaycastHit hit;
 int MaxBuildDist = 10;
 public Transform RetAdd;
 public Transform RetDelete;
 Color Block_Color = Color.blue;
 bool Block_Menu = false;

 // Use this for initialization
 void Start (){
     RetAdd = GameObject.Find("RetAdd").transform;
     RetDelete = GameObject.Find("RetDelete").transform;
 }
 
 // Update is called once per frame
 void Update (){
     if (Input.GetKeyDown(KeyCode.E))
         Block_Menu = !Block_Menu;
     if (Block_Menu)
         Time.timeScale = 0;
     if

     (!Block_Menu){
         if(Physics.Raycast(Camera.main.ScreenPointToRay(new Vector3((Screen.width / 2), (Screen.height / 2), 0)), out hit, MaxBuildDist)){
         RetAdd.GetComponent<Renderer>().enabled = true;
         if(hit.transform.tag == "Block"){
             RetAdd.transform.position = hit.transform.position + hit.normal;
             RetDelete.transform.position = hit.transform.position;
             RetDelete.GetComponent<Renderer>().enabled = true;
         }
         if(hit.transform.tag != "Block"){
             RetDelete.GetComponent<Renderer>().enabled = false;
             RetAdd.transform.position = new Vector3(hit.point.x, hit.point.y + 0.5f, hit.point.z);
         } 
     if(Input.GetMouseButtonDown(0)){
         GameObject block = (GameObject)Instantiate(Resources.Load("Block01"), RetAdd.transform.position, Quaternion.identity);
             block.GetComponent<Renderer>().material.color = Block_Color;
     }
         else if(Input.GetMouseButtonDown(1) && hit.transform.tag != "Floor"){
             Destroy(hit.transform.gameObject);
      

 }
 else{
     RetAdd.GetComponent<Renderer>().enabled = false;
     RetDelete.GetComponent<Renderer>().enabled = false;
 }

} } void OnGUI(){ if(Block_Menu) Block_Menu_GUI(); }

     void Block_Menu_GUI(){
         GUILayout.BeginVertical();
         if(GUILayout.Button("Green"))
         Block_Color = Color.green;
         if(GUILayout.Button("Red"))
             Block_Color = Color.red
         if(GUILayout.Button("Blue"))
             Block_Color = Color.blue
         GUILayout.EndVertical();

} }