LookAt but with Y axis facing the target

Questions & Answers
1

Hi guys, how would I rotate an object to look at another object but instead of forward (z axis) looking at the object, upwards (y axis) would be looking at the object.

2 
public class Yrotater : MonoBehaviour
{
	public Transform lookAt;
	void Update()
	{
		transform.up = lookAt.position - transform.position;
	}
}