See source for this via https://www.standard.co.uk/sport/football/fulham-transfer-news-and-targets-what-we-know-about-slavisa-jokanovic-s-summer-plans-a3888966.html
Argus reported this morning that Albion “still remain keen” to sign Button.
http://www.theargus.co.uk/sport/16343280.better-late-than-never-for-jason-steele-after-he-reveals-he-almost-joined-albion-a-year-ago/
This looks like its nearly done:
http://www.skysports.com/transfer/news/11741/11427116/brighton-set-to-sign-goalkeeper-david-button-from-fulham
http://www.theargus.co.uk/sport/16336176.albion-making-progress-on-fulham-goalkeeper-david-button-and-other-deals/