XP style look for file open dialog box in VC++

I want XP style look for my fileopen dialog box. Currently, I see windows 2000 style dialog box even when I am working in XP.

The Class which I am using is derived from CFileDialog

class CLFDlg : public CFileDialog
{
DECLARE_DYNAMIC(CLFDlg)
public:
CLFDlg(BOOL bOpenFileDialog, // TRUE for FileOpen, FALSE for FileSaveAs
LPCTSTR lpszDefExt = NULL,
LPCTSTR lpszFileName = NULL,
DWORD dwFlags = OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,
LPCTSTR lpszFilter = NULL,
CWnd* pParentWnd = NULL,
DWORD dwsize=0,
BOOL bVistaStyle=TRUE);
protected:
//{{AFX_MSG(CLFDlg)
virtual BOOL OnInitDialog();
//}}AFX_MSG
DECLARE_MESSAGE_MAP()