Vector3.MoveTowards give error Object reference not set to the instance of an object!

So i am making a game called potatoes vs tomatoes, i know cool name. And im trying to make the tomato move towards the potato(player) but when i use vector3.movetowards i get an error saying “Object reference not set to the instance of an object” PLEASE HELP!!!

Here is my script:

public var Speed : float; //you need float if * with Time.deltaTime
var Target : GameObject;
function Update ()
Target = GameObject.FindGameObjectWithTag(“Potato”);// just in case target is moving
if (Target != null)
transform.position = Vector3.MoveTowards(transform.position, Target.transform.position, Speed * Time.deltaTime; );
}else if (Target == null)
print("if there is more than one potato store them in array ");