I have a problem with a program to work out area of a circle - please help

[Interista]

import javax.swing.JOptionPane;
public class area
{
	public static void main (String[] args)
		{
			String a, area;
			double b, sum;

			a=JOptionPane.showInputDialog(null, "Enter circle radius:");
			
			b=Double.parseDouble(a);
			
			sum = b*b*3.1416;						
			
			area = DoubletoString(sum);
						
			OptionPane.showMessageDialog(null, "Circle of radius " + b + " has area " + area);
			
			System.exit(0);
		}
}

I need to convert the string the user enters into a double, do the sum, and put the sum back into a string to print out using JOptionPane

It is telling me...

area.java:15: error: cannot find symbol
area = DoubletoString(sum);
and has an arrow under the D

then it tells me

area.java:17:error: cannot find symbol
OptionPane.showMessageDialog(null, "Circle of radius " + b + " has area" + area);
and has an arrow under the )

What have I done wrong?

[sunde887]

Where did you define the method

DoubletoString(int x)

and what is

OptionPane

Check to make sure everything is spelled correctly.

['Major]

It should be

Double.toString(sum);

and

JOptionPane.showMessageDialog(null, "Circle of radius " + b + " has area " + area);

As the above poster said, make sure everything is spelled correctly.

[Interista]

Thanks!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!