Make sure only parent will be draggable.

Hello, I am working on Inventory/Character/Skill system. For now I have panel creation, Item generation etc. Now I am fighting with something.

I created Main Panel (215x215) Inside it another Panel with center align (215x180) And Inside (215x180) Panel I created 30 small Panels (34x34) using Grid Layout.

I want drag whole Panel (215x215) by clicking only that free area (look screen: http://screenshooter.net/102644289/ulpsrlr ). For now no matter where I click, (215x180) or (34x34) Pannels, everything is moving. How I can "block" dragging parent pannel by clicking child Panels? I want to put different script on that small (34x34) Pannels. I tried with block raycast etc. nothing helped.

Here is my dragging script attached to main Panel:

 using UnityEngine;
 using System.Collections;
 using UnityEngine.EventSystems;
 
 public class Draggable : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler {
 
     Vector2 MousePos;
     Vector2 NewPos;
 
     public void OnBeginDrag(PointerEventData EventData)
     {
         MousePos = new Vector2(EventData.position.x,EventData.position.y);
         MousePos.x = MousePos.x - EventData.pointerDrag.transform.position.x;
         MousePos.y = MousePos.y - EventData.pointerDrag.transform.position.y;
 
         Debug.Log (EventData.pointerDrag.name + "Started Drag.");
     }
 
     public void OnDrag(PointerEventData EventData)
     {
         NewPos = new Vector2(EventData.position.x, EventData.position.y);
 
         NewPos.x = NewPos.x - MousePos.x;
         NewPos.y = NewPos.y - MousePos.y;
         
         EventData.pointerDrag.transform.position = NewPos;
     }
 
     public void OnEndDrag(PointerEventData EventData)
     {
         MousePos = Vector2.zero;
         NewPos = Vector2.zero;
 
         Debug.Log (EventData.pointerDrag.name + "Stopped Drag.");
     }
 }