Currently i am trying to achieve one functionality where I have 2 sites like www.site1.com and other is https://excel.officeapps/live.com. Now i am trying to set some Key-value in second site(https://excel.officeapps/live.com) localstorage by hitting some button in first site.

After researching on this I Came to know it is Cross domain localstorage concept and only below approach i found everywhere.

https://jcubic.wordpress.com/2014/06/20/cross-domain-localstorage/

But the only issue i found here that i don't have control over second site so i can receive message and set it in localstorage of it. Can someone suggest on it whether it is even possible or not and if yes what alternate approach i can take.