function call inside OnClick Event?

I’m working with an Event System trigger on the 2d app. I was finally able to get the triggers to work onEnter, onExit, and onClick. With the onClick, I wanted to bring up a dialog box to confirm the selection( in this case to delete the item selected.) For whatever reason, the dialog function is not called.

public void GoEnter()
		{
			Debug.Log("you entered");
			IDText = MemberID.GetComponent<Text> ();
			IDText.color = Color.red;
			NameText=MemberName.GetComponent<Text>();
			NameText.color=Color.red;
		}
		
		
public void GoExit()
		{
			Debug.Log("you exited");
			IDText.color = Color.white;
			NameText.color=Color.white;
		}
		



public void GoClick()
		{
			IDText = MemberID.GetComponent<Text> ();
			IDText.color = Color.green;
			NameText=MemberName.GetComponent<Text>();
			NameText.color=Color.green;
			Debug.Log("you clicked");
			DeleteWindow();
		}

Come to find out, if you change the event to OnClick, OnEnter, OnExit, you do not need an event system added in. That does solve one problem, but I still cannot call any functions outside of this script. I added the reference at the top, but I get a null reference every time I try to access it. For whatever reason, it will not let me put anything(script or game object) into the public reference in the inspector. I don’t get it! Please help! Save my sanity!

	public Script2 _script2; --reference to test script

	public void OnClick()
	{
		IDText = MemberID.GetComponent<Text> ();
		IDText.color = Color.green;
		NameText=MemberName.GetComponent<Text>();
		NameText.color=Color.green;
		Debug.Log("you clicked");
		_script2.HelloScript2();
	}


Script2

	public void HelloScript2()
	{
		Debug.Log("Hello Script 2! This is Script 1 Calling!");
	}