Is a point on the positive side of the plane?

var goalLine1: Plane;
var goalLine2: Plane;
var leftSideLine: Plane;
var rightSideLine: Plane;

function GoalScored(ballPos: Vector3) {
	// If the ball is within the sidelines...
	if (!leftSideLine.GetSide(ballPos) && !rightSideLine.GetSide(ballPos)) {
		// If the ball is over goal line 1 then it's a goal for team 1...
		if (goalLine1.GetSide(ballPos))
			return 1;
		// ...else if the ball is over goal line 2 then it's a goal for team 2.
		else if (goalLine2.GetSide(ballPos))
			return 2;
	}
	
	// Otherwise, it isn't a goal for either team.
	return 0;
}

using UnityEngine;
using System.Collections;

public class Example : MonoBehaviour {
    public Plane goalLine1;
    public Plane goalLine2;
    public Plane leftSideLine;
    public Plane rightSideLine;
    int GoalScored(Vector3 ballPos) {
        if (!leftSideLine.GetSide(ballPos) && !rightSideLine.GetSide(ballPos))
            if (goalLine1.GetSide(ballPos))
                return 1;
            else
                if (goalLine2.GetSide(ballPos))
                    return 2;
                
        
        return 0;
    }
}

import UnityEngine
import System.Collections

public class Example(MonoBehaviour):

	public goalLine1 as Plane

	public goalLine2 as Plane

	public leftSideLine as Plane

	public rightSideLine as Plane

	def GoalScored(ballPos as Vector3) as int:
		if (not leftSideLine.GetSide(ballPos)) and (not rightSideLine.GetSide(ballPos)):
			if goalLine1.GetSide(ballPos):
				return 1
			elif goalLine2.GetSide(ballPos):
				return 2
		return 0