checking that user belongs to particular Group are Not

it is used to find the current loged in user belongs to 1 particular group are not...  

private bool CheckKaizenMentor(string groupName) 

        { 

            bool userVal = false; 

            SPSecurity.RunWithElevatedPrivileges(delegate() 

              { 

                  using (SPSite site = new SPSite(SPContext.Current.Site.Url)) 

                  { 

                      using (SPWeb web = site.OpenWeb()) 

                      { 

                          //For getting the Group Users for Kaizen mentor radio button list. 

                          SPGroup kcUsers = web.Groups[groupName]; 

                          foreach (SPUser user in kcUsers.Users) 

                          { 

                              if (currentUser == user.LoginName) 

                              { 

                                  userVal = true; 

                                  break; 

                              } 

                          } 

                      } 

                  } 

              }); 

  

            return userVal; 

        }