st: XTGLS & 2SLS

["John A Karikari" <KarikariJ@gao.gov>]

I'm estimating a "2SLS" procedure where the second stage uses XTGLS,
but the variance-covariance matrix of the 2SLS procedure would be
incorrect.  I would appreciate advice on how to obtain the corrected
variance-covariance matrix for the XTGLS, preferably a program that can
perform the procedure.  Thanks in advance.
*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/