How to make font bold on mouse over (c#)

Sorry, I’m still new to unity and unfamiliar with the language, basically my goal is to have my 3D text turn bold when mouseovered. Right now it changes color but I just can’t figure out what to use to turn it bold. I’ve tried fontStyle but I keep getting errors. What would I need to change to make the text turn bold?

The script looks like this:

public class ClickableText : MonoBehaviour {
	public bool isQuitButton = false;
	public bool isStartButton = false;
	public bool isOptionsButton = false;
	public bool isHelpButton = false;
	public bool isCreditsButton = false;

	
	

	
	void OnMouseEnter () {
		renderer.material.color = Color.red;

	}

	void OnMouseExit () {
		renderer.material.color = Color.white;
	}

	void OnMouseUp() {
			if (isQuitButton) {
				Application.Quit ();
				} 
				
			if (isStartButton) {
				Application.LoadLevel ("Level 1");
					}
				
			if (isHelpButton) {
			Debug.Log ("Help");
			}

			if (isOptionsButton) {
			Debug.Log ("Options");
			}

			if (isCreditsButton){
			Debug.Log ("Credits");
			}
		}

	}

Please excuse the messy script, but I wanted to have one script apply to all of the text options.
Thanks in advance

You can use:

 guiText.fontStyle = FontStyle.Bold;

You need to get access to the TextMesh component. There is not a shortcut like there is for guiText, so you need to use GetComponent(). The font must be marked as Dynamic in the Importer/Inspector. A few lines added to your code:

using UnityEngine;
using System.Collections;


public class ClickableText : MonoBehaviour {
	public bool isQuitButton = false;
	public bool isStartButton = false;
	public bool isOptionsButton = false;
	public bool isHelpButton = false;
	public bool isCreditsButton = false;

	private TextMesh tm;

	void Start() {
		tm = GetComponent<TextMesh>();
	}

	void OnMouseEnter () {
		renderer.material.color = Color.red;
		tm.fontStyle = FontStyle.Bold;
	}
	
	void OnMouseExit () {
		renderer.material.color = Color.white;
		tm.fontStyle = FontStyle.Normal;

	}
	
	void OnMouseUp() {
		if (isQuitButton) {
			Application.Quit ();
		} 
		
		if (isStartButton) {
			Application.LoadLevel ("Level 1");
		}
		
		if (isHelpButton) {
			Debug.Log ("Help");
		}
		
		if (isOptionsButton) {
			Debug.Log ("Options");
		}
		
		if (isCreditsButton){
			Debug.Log ("Credits");
		}
	}
}