// Written by:  Darren Gates & Ray Klefstad
// Date:        January 2000
// School:      U.C. Irvine

import java.io.*;

public class NumericInputExample
{
    public static void main(String argv[])
	throws IOException
    {
	try
	{
	    // get input and convert to a String
	    byte [] myInput = new byte[30];
	    System.out.print("Type a number: ");
	    System.in.read(myInput);
	    String myOutput = new String(myInput);
			
	    // convert the String to a double
	    Double d = new Double(myOutput);
	    double result = d.doubleValue();
			
	    // perform calculation and display
	    result = result * 2;
	    System.out.println("Twice that amount is: " + result);
	}
	catch (NumberFormatException e)
	{
	    System.out.println("That's not a number!");
	}
     }
}