[Vayd]

I wrote this:

import java.util.*; //Needed for Scanner Class


public class population //Begin class Population

{
	public static void main (String[] args)
				//Begin main function
		{
		//Variable declartion
		int starting,avg_daily, no_days;
		//create Scanner class for keyboard input
		Scanner keyboard = new Scanner(System.in);
		//Get a population
		System.out.println("Enter starting population of organisms: ");
		starting = keyboard.nextInt();
		//input validation
		if (starting<2)
		{
		//Display invalid messages
		System.out.println("Invalid Renter:");
		starting = keyboard.nextInt();
		}
		//Input average daily population
		System.out.println("Enter average daily population: ");
		avg_daily = keyboard.nextInt();
		if (avg_daily<0)//Validating daily percentage
		{
			System.out.println("Invalid Renter: ");
			avg_daily= keyboard.nextInt();
		}
		avg_daily=(avg_daily*starting)/100;
		//Inputting number of days
		System.out.println("Enter number of days: ");
		no_days = keyboard.nextInt();
		for(int i=0;i<no_days;i++)//loop repeats for all days
		{
			System.out.println("Day " + (i+1) +":" + starting);
			starting=starting+avg_daily;
		}
		
	}//End main function
}//end class Population

How would I write this so that it uses dialog boxes for the input questions? I know I would import javax.swing.JOptionPane; ... but if I put JOptionPane.showMessageDialog instead of System.out.println it will obviously give me errors, how do i fix that.