This is my first Java program. I am teaching myself Java, and I have a pretty good book I am using, but I am getting 5 compile errors, even though I am doing this by the book. Here is the code:

Code:
import javax.swing.JOptionPane;


// Create "Circle" class
public class Circle
{
	// Create default constructor that sets value of radius to 1
	public DefaultRadius()
	{
		defultRadius = 1;	
	}
	
	// Create main method
	public static void main(String[] args)
	{
		// Declare variables
		Radius defaultRadius = new DefaultRadius();			
		double radius = setRadius();				
			
		// Output total to dialog box
		JOptionPane.showMessageDialog(null, "A circle with a radius of " + newRadius + " has a diameter of " + diameter + " and an area of " + area);
		
		System.exit(0);

	}
	
	// Create method to set the value of the radius
	pubic static void setRadius()
	{
		// Declare variables
		double radiusString, radius;
		
		// Assign values to variables
		radiusString = JOptionPane.showInputDialog(null, 
		    "Enter the value of the radius of the circle.", "Enter Radius",
			 JOptionPane.INFORMATION_MESSAGE);
		
		// Convert inputs to integers and assign values to variables
		radius =Double.parseDouble(radiusString);	
		
		System.exit(0); 
		
	}
	
	// Create method to return the value of the radius
	pubic static double returnRadius(double radius)
	{
			
		double newRadius;		
		newRadius = radius;
		return newRadius;
			
	}
	
	// Create method to compute and return the circle's diameter
	pubic static double computeDiameter(double newRadius)
	{			
		double diameter;		
		diameter = newRadius * 2;
		return diameter;			
	}
	
		// Create method to compute and return the circle's area
	pubic static double computeDiameter(double newRadius)
	{			
		double area;		
		area = (newRadius * newRadius) *3.14;
		return area;			
	}


}

Here are the errors:

invalid method declaration; return type required
public DefaultRadius()
^
<identifier> expected
pubic static void setRadius()
^
<identifier> expected
pubic static double returnRadius(double radius)
^
<identifier> expected
pubic static double computeDiameter(double newRadius)
^
<identifier> expected
pubic static double computeDiameter(double newRadius)
^