Login Username And Password With Facebook for iOS/Iphone

==>  Working With login in ios 5 and ios 6 , Using  FBLoginView Class ,
    simplest way to login into facebook using Facebook sdk .

    FBLoginView * pFBLoginViewObj = [[FBLoginView alloc] init];
    [pFBLoginViewObj setFrame:self.view.frame];
    pFBLoginViewObj.delegate = self;//optional
    [self.view addSubview:pFBLoginViewObj];