remove user from sharepoint group

The trick is

SPUser user = web.EnsureUser(peCheckUser.Accounts[0].ToString());

                            SPGroupCollection collGroups = user.Groups;
                            if (collGroups.Count > 0)
                            {
                                foreach (SPGroup oGroup in collGroups)
                                {
                                    oGroup.RemoveUser(user);
                                }
                                strError += "User Removed Successfully...!";
                            }


thanks to author @ http://sharepoint2010tutorialnew.blogspot.com/2011/12/deleting-user-within-sharepoint-group.html