Reading odd and even integers

I'm trying to write a program in for school that will read whether a number is odd or even, and I just can't get anything to work.
I'm guessing I need if statements but I can't figure out exactly what, this is what I have so far...

import javax.swing.JOptionPane;

public class Even {
public static void main (String args[])
{
String num1;
int n1,odd,even;

num1 = JOptionPane.showInputDialog("Please type in an integer:");

n1 = Integer.parseInt(num1);
odd = ? ;
even = ? ;


if( ? )JOptionPane.showMessageDialog(
null,"The number is "+odd,"Results",JOptionPane.INFORMATION_MESSAGE);
else JOptionPane.showMessageDialog(
null,"The number is "+even,"Results",JOptionPane.INFORMATION_MESSAGE);

System.exit (0);
}
}

The ?'s are where I', completely lost, someone Please help!!!