Program to list the users in the Active Directory

static void Main(string[] args)
{
    string groupName = "Domain Users";
    string domainName = "";
 
    PrincipalContext ctx = new PrincipalContext(ContextType.Domain, domainName);
    GroupPrincipal grp = GroupPrincipal.FindByIdentity(ctx, IdentityType.SamAccountName, groupName);
 
    if (grp != null)
    {
         foreach (Principal p in grp.GetMembers(false))
            {
                Console.WriteLine(p.SamAccountName + " - " + p.DisplayName);
            }
 
 
        grp.Dispose();
        ctx.Dispose();
        Console.ReadLine();
    }
    else
    {
        Console.WriteLine("\nWe did not find that group in that domain, perhaps the group resides in a different domain?");
        Console.ReadLine();
    }
}