suma de los N primeros numeros naturales

/*
* EjWhile.java
*
* Created on 23 de abril de 2007, 07:14 PM
*/

/**
*
* @author ALUMNO
*/
public class EjWhile extends javax.swing.JFrame {

/** Creates new form EjWhile */
public EjWhile() {
initComponents();
}

/** This method is called from within the constructor to
* initialize the form.
* WARNING: Do NOT modify this code. The content of this method is
* always regenerated by the Form Editor.
*/
// //GEN-BEGIN:initComponents
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
jScrollPane1 = new javax.swing.JScrollPane();
jTextPane1 = new javax.swing.JTextPane();
jScrollPane2 = new javax.swing.JScrollPane();
jTextPane2 = new javax.swing.JTextPane();
jLabel2 = new javax.swing.JLabel();
jButton1 = new javax.swing.JButton();

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jLabel1.setText("N");

jScrollPane1.setViewportView(jTextPane1);

jScrollPane2.setViewportView(jTextPane2);

jLabel2.setText("Suma");

jButton1.setText("Evaluar");
jButton1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton1ActionPerformed(evt);
}
});

org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(layout.createSequentialGroup()
.add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(layout.createSequentialGroup()
.add(20, 20, 20)
.add(jLabel1))
.add(layout.createSequentialGroup()
.addContainerGap()
.add(jLabel2)))
.add(19, 19, 19)
.add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(jScrollPane2, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 118, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
.add(jScrollPane1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 114, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE))
.addContainerGap(223, Short.MAX_VALUE))
.add(org.jdesktop.layout.GroupLayout.TRAILING, layout.createSequentialGroup()
.addContainerGap(178, Short.MAX_VALUE)
.add(jButton1)
.add(149, 149, 149))
);
layout.setVerticalGroup(
layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(layout.createSequentialGroup()
.add(15, 15, 15)
.add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.TRAILING)
.add(jScrollPane1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
.add(jLabel1))
.add(34, 34, 34)
.add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.TRAILING)
.add(jScrollPane2, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
.add(jLabel2))
.add(41, 41, 41)
.add(jButton1)
.addContainerGap(54, Short.MAX_VALUE))
);
pack();
}// //GEN-END:initComponents

private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_jButton1ActionPerformed
// TODO add your handling code here:
int n,i,S;
n = Integer.parseInt(jTextPane1.getText());

S = 0; i = 0;
while(i<=n){
S = S + i;
i++; // i = i + 1
}
jTextPane2.setText(String.valueOf(S));

}//GEN-LAST:event_jButton1ActionPerformed

/**
* @param args the command line arguments
*/
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new EjWhile().setVisible(true);
}
});
}

// Variables declaration - do not modify//GEN-BEGIN:variables
private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JTextPane jTextPane1;
private javax.swing.JTextPane jTextPane2;
// End of variables declaration//GEN-END:variables

}