Java SE (Java Platform, Standard Edition)

I've just started swing, and had a few promising results, until my code got a little more complex. I've run into a problem, and I don't know enough to really understand why it's there. Basically, I have some code (which I will paste here after my explanation) that is supposed to create a window and add in a text area and text field. The problem is, the JPanel and JScrollPane variables aren't recognized as existent by the compiler. I can seem to figure out why.

Here's the entire code I'm working with:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

class TerraGUI {
	private static void createAndShowGUI() {
		JFrame frame = new JFrame("Main Window");
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		JPanel mainPane = new JPanel();
		mainPane.setPreferredSize(new Dimension(800, 600));
		frame.getContentPane().add(mainPain);

		JScrollPane chatPain = new JScrollPane();
		chatPain.setVerticalAlignment(JLabel.BOTTOM);
		JTextField textField = new JTextField(20);
		JTextArea textArea = new JTextArea();
		textArea.setColumns(50);
		textArea.setRows(10);
		textArea.setEditable(false);
		chatPane.add(textArea);
		chatPane.add(textField);
		frame.getContentPane().add(chatPain);

		frame.pack();
		frame.setVisible(true);
	}
	
	public static void main(String[] args) {
		SwingUtilities.invokeLater(new Runnable() {
			public void run() {                
				createAndShowGUI();
			}
		});
	}
}

And here's the compiler errors:

C:\Program Files\Java\jdk1.6.0_16\bin\javac "TerraGUI.java" (in directory: C:\Users\Cyle Dawson\Documents\Java\Terra)
TerraGUI.java:12: cannot find symbol
symbol  : variable mainPain
location: class TerraGUI
  frame.getContentPane().add(mainPain);
                             ^
TerraGUI.java:15: cannot find symbol
symbol  : method setVerticalAlignment(int)
location: class javax.swing.JScrollPane
  chatPain.setVerticalAlignment(JLabel.BOTTOM);
          ^
TerraGUI.java:21: cannot find symbol
symbol  : variable chatPane
location: class TerraGUI
  chatPane.add(textArea);
  ^
TerraGUI.java:22: cannot find symbol
symbol  : variable chatPane
location: class TerraGUI
  chatPane.add(textField);
  ^
4 errors
Compilation failed.

Can anyone explain to me why the variables aren't recognized? I'm supposed to have a small, semi-functioning GUI by Sunday and this is confounding me.