How can I make the score counter use the custom font?

I have been trying to use a custom font on a score counter and I keep getting errors when I try to call yourFont.

using UnityEngine; using System.Collections;

public class HudScript : MonoBehaviour {

 public Font yourFont;
 float playerScore = 0;

 

 void Update () 
 {
     playerScore += Time.deltaTime;
 }

 public void IncreaseScore(int amount)
 {
     playerScore += amount;
 }

 void OnDisable()
 {
     PlayerPrefs.SetInt ("Score", (int)(playerScore * 100, yourFont));
 }

 void OnGUI()
 {
     GUI.Label (new Rect (10, 10, 100, 30), "Score: " + (int)(playerScore * 100));
 }

}