Thread: Need help with input/output error

I am writing a program that needs me to input the assessed value of a home and then the output should be stored in a file. The program deals with property tax. I'm getting the error

Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:840)
at java.util.Scanner.next(Scanner.java:1461)
at java.util.Scanner.nextDouble(Scanner.java:2387)
at Problem4.main(Problem4.java:33)

Here is my full code

// Stefan Springhetti
// Problem4
// 2/1/2001
 
import java.io.*;
import java.util.*;
import javax.swing.*;
 
public class Problem4 {
 
			public static void main(String[] args)
											throws FileNotFoundException
			{
			String inputStr;
			double assessedValue; 
			double taxableAmount;
			double taxRate;
			double propertyTax;
 
 
			taxableAmount = .92 * assessedValue;
			taxRate = 1.05;
			propertyTax = 1.05 * 92;
 
			Scanner inFile =
				new Scanner(new FileReader("tax.dat"));
 
			PrintWriter outFile = new PrintWriter("output.dat");
 
			inputStr = JOptionPane.showInputDialog
									("Enter the assessed value");
			assessedValue = Double.parseDouble(inputStr);
 
 
			outFile.printf("Assesed Value: $" + String.format("%.2f", assessedValue) + "\n"
			+ "Taxable Amount: $" +  String.format("%.2f", taxableAmount)+ "\n"
			+ "Tax Rate: $" + String.format("%.2f", taxRate) + "\n" 
			+ "Property Tax: $" + String.format("%.2f", propertyTax));
 
 
			outFile.close(); 
 
			}
}

when i executed this program on my machine , its executing fine.