Problem with SWT Menu Item

[faisal hameed]

I am new to RCP and after reading a lot of tutorials I tried to practice one tutorial from the following link to create a menuItem.when i run the program the menuItem is disable and not working.
IBM

My xml file is as follow.

  

<?xml version="1.0" encoding="UTF-8"?>
<?eclipse version="3.2"?>
<plugin>

   <extension
         id="application"
         point="org.eclipse.core.runtime.applications">
      <application>
         <run
               class="swt_project.Application">
         </run>
      </application>
   </extension>
   <extension
         point="org.eclipse.ui.perspectives">
      <perspective
            name="RCP Perspective"
            class="swt_project.Perspective"
            id="SWT_Project.perspective">
      </perspective>
   </extension>
   <extension
         point="org.eclipse.ui.handlers">
      <handler
            class="ExitHandler"
            commandId="SWT Project.exit">
      </handler>
   </extension>
   <extension
         point="org.eclipse.ui.commands">
      <category
            description="Command Category Description"
            id="SWT Project.commandCat"
            name="CommCatName">
      </category>
      <command
            category="SWT Project.commandCat"
            defaultHandler="ExitHandler"
            id="SWT Project.exit"
            name="exitCommand">
      </command>
   </extension>
   <extension
         point="org.eclipse.ui.menus">
      <menuContribution
            locationURI="menu:org.eclipse.ui.main.menu">
         <menu
               id="fileMenu"
               label="File"
               mnemonic="f">
            <command
                  commandId="SWT Project.exit"
                  label="Exit"
                  mnemonic="e"
                  style="push"
                  tooltip="Click here to Exit">
            </command>
         </menu>
      </menuContribution>
   </extension>
</plugin>

  

My ApplicationWorkbenchWindowAdvisor class is as follow

 
package swt_project;

import org.eclipse.swt.graphics.Point;
import org.eclipse.ui.application.ActionBarAdvisor;
import org.eclipse.ui.application.IActionBarConfigurer;
import org.eclipse.ui.application.IWorkbenchWindowConfigurer;
import org.eclipse.ui.application.WorkbenchWindowAdvisor;

public class ApplicationWorkbenchWindowAdvisor extends WorkbenchWindowAdvisor {

    public ApplicationWorkbenchWindowAdvisor(IWorkbenchWindowConfigurer configurer) {
        super(configurer);
    }

    public ActionBarAdvisor createActionBarAdvisor(IActionBarConfigurer configurer) {
        return new ApplicationActionBarAdvisor(configurer);
    }
    
    public void preWindowOpen() {
        IWorkbenchWindowConfigurer configurer = getWindowConfigurer();
        configurer.setInitialSize(new Point(400, 300));
        configurer.setShowCoolBar(false);
        configurer.setShowStatusLine(false);
        configurer.setShowMenuBar(true);
        configurer.setTitle("Hello RCP");
    }
}