Front-end view for a specific Event page

[RobertZSun]

After the user click on the "Join" button, that button will change its background color to a blue background, and from "Join" to "Joined", and click another time to the "Joined" button, it will become to "Join" button again, back to former status, it is just, click "Join", the button changed to "Joined", right now, the user is joined in that event, click on "Joined", it changes to "Join", right now, user is not participating in that event. The second picture will show the status after click "Join".