I am having an application in which I have added one Tab in it also it has a default Home Tab.

Now I need to open up another visualforce page on a button click.

I have used PageReference here : 

        public PageReference GoToMasterPage(){
            PageReference pr = new PageReference('/apex/MySecondPage');
            pr.setRedirect(true); 
            return pr;
    }

whenever it gets eecuted it opens up correct vf page but, the focus always shifts to Home Tab which was present by default.

I do not want focus to shift to Home tab or any other tab. I need focus on the currently selected tab itself.
How can I achieve this.

Thanks in Advance.