//
//		File: Convert1.java
//		....
//
//		The code will read a number, and display its double

import javax.swing.*;

class Convert1
{
	public static void main(String[] args)
	{
		// declare var.
		String temp;
		int num;
		boolean go = true;

		// use a loop
		while(go)
		{
			// read a String type
			temp = JOptionPane.showInputDialog("Input a number: "); //	"12"

			// convert the string to int (p.110)
			num = Integer.parseInt(temp);

			// compute & out
			JOptionPane.showMessageDialog(null, "Its double is " + 2*num);

			temp = JOptionPane.showInputDialog("Want to quit (y/n): ");
			temp = temp.toLowerCase();	// "Y" --> "y"
			if( temp.equals("y"))
				go = false;
		}

		// exit GUI from the program
		System.exit(0);

	}
}