Autherisation in Share point 2007

[pkker]

fter my authentication i was trying to add the user to the sharepoint site groups for the authorization of the user by using the code below

SPSecurity.RunWithElevatedPrivileges(delegate

{

SPWeb web = new SPSite(this.Request.Url.AbsoluteUri.Replace(this.Request.Url.LocalPath, "")).OpenWeb();

web.AllowUnsafeUpdates = true;

//Assign role and add user to site

SPRoleAssignment spRoleAssignment =new SPRoleAssignment(login.UserName, "", login.UserName, "");

//Using Contribute, might need high access

SPRoleDefinition spSPRoleDefinition =web.RoleDefinitions["Contribute"]

spRoleAssignment.RoleDefinitionBindings.Add(spSPRoleDefinition);

web.RoleAssignments.Add(spRoleAssignment);

//Update site

web.Update();

Microsoft.SharePoint.Administration.SPWebApplication webApp = web.Site.WebApplication;

webApp.FormDigestSettings.Enabled = false;

SPGroup spGroup = web.SiteGroups["Authentication test Members"];

spGroup.OnlyAllowMembersViewMembership = false;

//Add and update group with new user

spGroup.AddUser(login.UserName, "", login.UserName, "");

spGroup.Update();

webApp.FormDigestSettings.Enabled = true;

if (web != null)

{

web.Dispose();

}

//web.AllowUnsafeUpdates = true;

//// add user to group and update it

//associatedMemberGroup.AddUser(defaultProvider + ":" + sUserName, sEmail, sUserName, "");

//associatedMemberGroup.Update();

//web.AllowUnsafeUpdates = false

//web.Dispose();

});

Error:The user does not exist or is not unique


Could you provide me the solution for adding users to the site groups for Authorization.