Random does not contain a defintion for Range

Unity says that if i save my script can you help me?

Here is the Script:
using UnityEngine;
using System.Collections;

public class t1 : MonoBehaviour {

	int message = 0;    
	
		public void Start()
		{
			message = UnityEngine.Range(1,29);
		}
	
		public void OnGUI()
		{
			if(message == 1)
				guiText.text = "42";
			if(message == 2)
				guiText.text = "1 byte + 0.5 byte = Monochrome";
			if(message == 3)
				guiText.text = "This is a random Text";
			if(message == 4)
				guiText.text = "Play it in less than one second!";
			if(message == 5)
				guiText.text = "Runs under 2000 fps";
			if(message == 6)
				guiText.text = "Hello Computer :)";
			if(message == 7)
				guiText.text = "Is your slave!";
			if(message == 8)
				guiText.text = "XB-70 Valkyrie!";
			if(message == 9)
				guiText.text = "I want a A-380.";
			if(message == 10)
				guiText.text = "Not for under 0.01$";
			if(message == 11)
				guiText.text = "Hasn't any value.";
			if(message == 12)
				guiText.text = "I've an E-Mail acount.";
			if(message == 13)
				guiText.text = "Yellow!!!";
			if(message == 14)
				guiText.text = "Colder than a Pentium(r) 4.";
			if(message == 15)
				guiText.text = "Runs maybe on your Computer.";
			if(message == 16)
				guiText.text = "Needs 5TB of RAM.";
			if(message == 17)
				guiText.text = "Annoying!";
			if(message == 18)
				guiText.text = "Short play!";
			if(message == 19)
				guiText.text = "I hope you like it!";
			if(message == 20)
				guiText.text = "It's made during Apollo 13!";
			if(message == 21)
				guiText.text = "26 Different Text's.";
			if(message == 22)
				guiText.text = "64bit rocks!";
			if(message == 23)
				guiText.text = "Can speak English.";
			if(message == 24)
				guiText.text = "Give it all your money!";
			if(message == 25)
				guiText.text = "Is pointless!";
			if(message == 26)
				guiText.text = "Has an idea!!!";
			if(message == 27)
				guiText.text = "Yeah, Bluescreen.";
			if(message == 28)
				guiText.text = "Hi Mr. Trevor Phillips.";
			if(message == 29)
				guiText.text = "Runs with oxygen";
		}
}

Try this…

Random.Range(minvalue,maxvalue)

minvalue : include
maxvalue : exclude