How to create new response

[abolabo]

Thanks a lot,i missed that part. 

Another question,is it possible to use existing category and product model and copy it into the model folder?

inside hook? yes
just load model that needed via $that->loadModel('catalog/product'); and call $that->model_catalog_product->method();

[yonghan]

How about from the response controller?

[abolabo]

inside extension controllers the same way as in core-controllers

[yonghan]

Thanks a lot for the help abolabo.I got it working as expected.Once again thanks a lot.