processFormRequest(OAPageContext pageContext, OAWebBean webBean) in OAF?

This method we will use if you want any changes after page load.suppose after click on button kind of if you want to display any results. user actions on the page.

Sample code from Controller

/*===========================================================================+
 |   Copyright (c) 2001, 2005 Oracle Corporation, Redwood Shores, CA, USA    |
 |                         All rights reserved.                              |
 +===========================================================================+
 |  HISTORY                                                                  |
 +===========================================================================*/
package xxamw.oracle.apps.po.requisition.webui.webui;

import oracle.apps.fnd.common.VersionInfo;
import oracle.apps.fnd.framework.webui.OAControllerImpl;
import oracle.apps.fnd.framework.webui.OAPageContext;
import oracle.apps.fnd.framework.webui.beans.OAWebBean;

/**
 * Controller for ...
 */
public class MyCO extends OAControllerImpl
{
  public static final String RCS_ID="$Header$";
  public static final boolean RCS_ID_RECORDED =
        VersionInfo.recordClassVersion(RCS_ID, "%packagename%");

  /**
   * Layout and page setup logic for a region.
   * @param pageContext the current OA page context
   * @param webBean the web bean corresponding to the region
   */
  public void processRequest(OAPageContext pageContext, OAWebBean webBean)
  {
    super.processRequest(pageContext, webBean);
  }

  /**
   * Procedure to handle form submissions for form elements in
   * a region.
   * @param pageContext the current OA page context
   * @param webBean the web bean corresponding to the region
   */
  public void processFormRequest(OAPageContext pageContext, OAWebBean webBean)
  {
    super.processFormRequest(pageContext, webBean);
  }


}