How to show OpenFileDialogBox in VC++

CFileDialog *CommDlg;
char Filetype[] = "All Files (*.EXE)|*.EXE||";
CommDlg = new CFileDialog(TRUE, NULL, NULL,OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,Filetype,this);
CommDlg->DoModal();

UpdateData(TRUE);
CString Filename;
CString m_AppPath = CommDlg->GetPathName();
if(m_AppPath.IsEmpty())
{
delete CommDlg;
return;
}
Filename = CommDlg->GetFileName();
int Filesize = Filename.GetLength();