function value = znorm1 ( z )

%*****************************************************************************80
%
%% znorm1() evaluates the normal CDF from 0 to Z.
%
%  Licensing:
%
%    This code is distributed under the MIT license.
%
%  Modified:
%
%    05 February 2008
%
%  Author:
%
%    John Burkardt
%
%  Input:
%
%    real Z, the upper limit.
%
%  Output:
%
%    real VALUE, the probability that a standard
%    normal variable will lie between -oo and Z.
%
  value = 0.5 * erf ( z / sqrt ( 2.0 ) );

  return
end
