How to attach a script to a variable?

Questions & Answers
1

I am making a game where you can build bases/armies, and destroy your enemies base/army.
My Problem is that my building controller has a variable for the player controller. When I place a new building the variable for the player controller becomes null. Is there any way I can automatically attach my player controller?

Here is my curent building controller script:

using UnityEngine;
using System.Collections;

using UnityEngine;
using System.Collections;

public class BUILDINGCONTROLS: MonoBehaviour {

	public playercontrols PLAYERPORT; //PLAYER CONTROLS SCRIPT
	public Transform MYWAYPOINT; //For Unit Training
	public Texture HIGHLIGHT; //Texture for when the mouse is over the building
	public Texture NORM; //Normal Texture
	void OnMouseOver ()
	{
		renderer.material.mainTexture = HIGHLIGHT;
		if (Input.GetMouseButtonDown (0)) {
			//Send info to the player
			PLAYERPORT.selected_unit = transform.tag;
			PLAYERPORT.selected_unit_transform = MYWAYPOINT.transform;
			PLAYERPORT.selected_unit_type = "Building";
			PLAYERPORT.selected_object = gameObject;
		}
	}
	void OnMouseExit(){
		renderer.material.mainTexture = NORM;
	}
}
2

You could find the player by name or tag, get the script with GetComponent and assign it to the variable PLAYERPORT at Start:

    ...
    void Start(){
        GameObject player = GameObject.FindWithTag("Player");
        PLAYERPORT = player.GetComponent< playercontrols>();
    }
    ...