Problem with looking to target OnMouseEnter

I want my game object to look at me when I hover over it with the mouse, but I can’t get it to work how I want. Instead of waiting until I hover, each of the gameobjects I attached the script to look at me right when I start it up. Here is my script:

using UnityEngine;
using System.Collections;

public class hoverScript : MonoBehaviour {
	
	public Transform target;
	public string levelToLoad;
	public AudioClip soundhover;
	public AudioClip beep;
	public int rotationSpeed;
	public bool QuitButton = false;
	public bool onHover = false;
	
	private Transform myTransform;
	
	//On Startup
	void Awake() {
		myTransform = transform;
	}
	
	void OnMouseEnter() {
		audio.PlayOneShot( soundhover);
		onHover = true;	
	}
	
	void OnMouseUp() {
		audio.PlayOneShot( beep);
		
		if( QuitButton) {
			Application.Quit();
		}
		else {
			Application.LoadLevel( levelToLoad);
		}
	}
	
	// Update is called once per frame
	void Update () {
			if( onHover = true) {
				//look to camera
				myTransform.rotation = Quaternion.Slerp( myTransform.rotation, Quaternion.LookRotation( target.position - myTransform.position), rotationSpeed * Time.deltaTime);
			}
	}
}

I’m guessing it has something to do with the booleans, but I can’t figure it out. If someone else could help I would really appreciate it!

The comparison operator is ‘==’. Single ‘=’ is assignment, so line 39 could be:

if (onHover == true)

Actually a better test which is the same logic:

     if(onHover) {