
I added library project inside eclipse. But i got following error
Use same android-support-v4.jar library in both library and your main project.
To do this remove android-support-v4.jar file form both library and your main projects build path and then remove android-support-v4.jar from your libs path. Then reinsert same android-support-v4.jar in both library and main project. Then use add to build path to add lib to your projects.
This will solve your problem.

How to Add Support Lib in Project :
To add latest support lib to your android project do these steps :
Android ToolsAdd Support LibraryThen follow the screen instructions and this will add latest support library to your libs folder.

Now right click on android-support-v4.jar file in libs folder and Add it to build path as I described. You will have the latest support lib in your project.
UPDATE
As 'Doctoror Drive' said you only need to add support library in your library project. So only add support library to your library project.