Capture ContextMenu click event in C# .Net 3.0

[snehal12345]

I have created 1 contextmenu for a listbox in C#.net 3.0 . For that context menu I have written one event handler for mouseup event . But when i click on contextmenu item that event is not captured. I have done following:
{ /*in constructor of main window */
listbox1.ContextMenu.Items.Add("save");
listbox1.ContextMenu.MouseUp += new System.Window.Input.MouseButtonEventHandler(Contex tMenu_MouseUp);
....
}
ContextMenu_MouseUp(object sender, System.Window.Input.MouseButtonEventArgs e )
{
MessageBox.Show("Contextmenu item selected");
}

Please help...