Class won't compile

[Memnoch1207]

When I try to compile my class, I keep getting this error.

error CS0246: The type or namespace name 'Dictionary' could not be found (are your missing a using directive or an assembly reference?)

error CS0246: The type or namespace name 'dict' could not be found (are you missing a using directive or an assembly reference?)

I am writing the code in notepad and compiling with the command line.

here's my code

using System;
using System.Collections;

class CH1_12 {

	public static void Main()
	{
		Dictionary dict = new Dictionary();

		dict.Add(1, "C++");
		dict.Add(2, "C");
		dict.Add(3, "Ada");
		dict.Add(4, "APL");
		dict.Add(5, "VB");
		dict.Add(6, "C#");
		dict.Add(7, "Java");
		dict.Add(8, "FORTRAN");

		//Print out the list
		Console.WriteLine("Before Deleting Anything");
		
		foreach(DictionaryEntry de in dict)
		{
			Console.WriteLine("Entry Key {0} Value {1}", de.Key, de.Value);
		}

		dict.Remove(4);
		dict.Remove(7);
	
		Console.WriteLine("After Deletions");
		
		foreach(DictionaryEntry de in dict)
		{
			Console.WriteLine("Entry Key {0} Value {1}", de.Key, de.Value);
		}		

	}
}

and ideas on what's going on?????