public void BrowseForFile(EventHandler <BrowseCompleteEventArgs> onComplete, string[] fileExts = null, string startupFolderRelativePath = null, object userState = null)
{
if (_appServices == null)
{
throw new Exception("Application Services are unavailable.");
}
_appServices.BrowseForFile(onComplete, fileExts, startupFolderRelativePath, userState);
}