iPhone: objc_class_name_TTTabStrip symbol not found build error

I am trying to implement 'scrollview' effect in 'Tabbar' which has 'TabItems'. I found that the good example is from 'facebook' open source 'TTCatlog' project 'Tabs' section. So i included all the source from it to my project and trying to build it. I have followed the following links to go ahead on this: How to create a horizontal scrolling view on iPhone? source: http://github.com/facebook/three20/tree/master/samples/

My calling code is like below:

_tabBar1 = [[TTTabStrip alloc] initWithFrame:CGRectMake(10, 68, 300, 28)];
_tabBar1.tabItems = [NSArray arrayWithObjects:
                     [[[TTTabItem alloc] initWithTitle:@"Item 1"] autorelease],
                     [[[TTTabItem alloc] initWithTitle:@"Ite开发者_如何学运维m 2"] autorelease],
                     [[[TTTabItem alloc] initWithTitle:@"Item 3"] autorelease],
                     [[[TTTabItem alloc] initWithTitle:@"Item 4"] autorelease],
                     [[[TTTabItem alloc] initWithTitle:@"Item 5"] autorelease],
                     [[[TTTabItem alloc] initWithTitle:@"Item 6"] autorelease],
                     [[[TTTabItem alloc] initWithTitle:@"Item 7"] autorelease],
                     [[[TTTabItem alloc] initWithTitle:@"Item 8"] autorelease],
                     [[[TTTabItem alloc] initWithTitle:@"Item 9"] autorelease],
                     [[[TTTabItem alloc] initWithTitle:@"Item 10"] autorelease],
                     nil];
[self.navigationController.view addSubview:_tabBar1];

My project folder as like below:

..../iphone/MyProgram/MyProgram.xcodeproj

..../iphone/Three20/src/Three20....

In my project settings for header search path, I have

../Three20/src

But when i try to build it, it throws the following error:

"objc_class_name_TTTabStrip symbol not found" "objc_class_name_TTTabItem symbol not found" I see there, all these files (.h and .m) are availbale there.

Could someone please help what's wrong there and how do i get rid of this issue and continue working with it?

---

Generally this error throw due to you not importing the appropriate class where you want to implement the method of that class(like inheritance).

#import "your_class_name.h"

@class your_class_name