Simple Variable Problem

[DaoK]

I know that code is really basic but It show my question:

package test2;
import javax.swing.JOptionPane;
public class test2 {
  public static void main ( String args [])
    {
      int x,
          y,
          z,
          resultat;
      String xVal,
             yVal,
             zVal;
      xVal =
        JOptionPane.showInputDialog ( "Voyez entrer un nombre" );
      yVal =
        JOptionPane.showInputDialog ( "Voyez entrer un secon nombre");
      zVal =
        JOptionPane.showInputDialog ( "Voyez entrer un dernier nombre");
      x = Integer.parseInt (xVal);
      y = Integer.parseInt (yVal);
      z = Integer.parseInt (zVal);
      resultat = ( x * y * z );

      JOptionPane.showMessageDialog (
        null, resultat, "Le produit est : ",
        JOptionPane.INFORMATION_MESSAGE);
      }
}

I have an error on that line : null, resultat, "Le produit est : ",
Why I have an error ?