i want to check that weather user is logged in Facebook or my website so if he is loggined to Facebook so he will not allow to enter from website. the problem is that there will be two different client so what should i do to solve my issue??
Is there another way to frame you problem? Because I can think of two easy ways for a user to circumvent that: 1. IOpen Facebook in a private browsing session, or your site. You will not be able to know if they are logged in to facebook. 2. Open facebook in a second browser. Your site in chrome, facebook in safari or IE or something.
In short - you may be able to detect if facebook is open in the same browser, but you will not be able to definitively prevent this.
(And let's not forget that you user is also possibly connected to facebook thru their mobile device as well. So...)
Does you whole project hinge on not being connected to facebook?