          SUBROUTINE XERBLA( SRNAME, INFO )
    *
    *  -- LAPACK auxiliary routine (version 3.1) --
    *     Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
    *     November 2006
    *
    *     .. Scalar Arguments ..
          CHARACTER*6        SRNAME
          INTEGER            INFO
    *     ..
    *
    *  Purpose
    *  =======
    *
    *  XERBLA  is an error handler for the LAPACK routines.
    *  It is called by an LAPACK routine if an input parameter has an
    *  invalid value.  A message is printed and execution stops.
    *
    *  Installers may consider modifying the STOP statement in order to
    *  call system-specific exception-handling facilities.
    *
    *  Arguments
    *  =========
    *
    *  SRNAME  (input) CHARACTER*6
    *          The name of the routine which called XERBLA.
    *
    *  INFO    (input) INTEGER
    *          The position of the invalid parameter in the parameter list
    *          of the calling routine.
    *
    * =====================================================================
    *
    *     .. Executable Statements ..
    *
          WRITE( *, FMT = 9999 )SRNAME, INFO
    *
          STOP
    *
     9999 FORMAT( ' ** On entry to ', A6, ' parameter number ', I2, ' had ',
         $      'an illegal value' )
    *
    *     End of XERBLA
    *
          END