Global name space error c#

 using UnityEngine;
 using System.Collections;
 
 ****"public class BuildingManager : MonoBehaviour {"****
     
     public GameObject[] buildings;
     private BuildingPlacement buildingPlacement;
     
     // Use this for initialization
     void Start () {
         buildingPlacement = GetComponent<BuildingPlacement>();
     }
     
     // Update is called once per frame
     void Update () {
         
     }
     
     void OnGUI() {
         if (GUI.Button (new Rect (Screen.width / 20, Screen.height / 15 + Screen.height / 12 * i, 100, 30), "General" ) {
 
         for (int i = 0; i <buildings.Length; i ++) {
             if (GUI.Button (new Rect (Screen.width / 20, Screen.height / 15 + Screen.height / 12 * i, 100, 30), buildings [i].name)) {
                 buildingPlacement.SetItem (buildings [i]);
             }
         }
     }
 }
         }