Js how to access text in the canvas from a script

i am trying to make a scoring system and i already have the debug output statements working for the score but i cannot seem to find any way to access and change the text in the canvas. i am working on unity version 5.0 in java script

function update_score () {

ScoreText.text = "Score: " + snake.GetComponent(MoveSnake).Score;


Debug.Log(snake.GetComponent(MoveSnake).Score);

}

private var textField : UI.Text;

 void Start () {
     textField = GetComponent(UI.Text);
     textField.text = "Ur text";
  }

@Mutton