HAILEY TODAY, GONE TOMORROW

No sooner than Hailey Glassman is added to the Gosselin official website than POOF - she's gone.

RADARonline.com reports that Jon Gosselin's GF, tummy tuck doc daughter; Hailey Glassman, was added to the official website yesterday.

Underneath the section containing information about how to hire Jon and Kate for public appearances, a new box of information was created that said: "Please Note: Hailey Glassman does not have a Facebook account at  all.

"Her official Twitter account is HaileyGlassman1 and Jon's is JonGosselin1."

But now www.sixgosselins.com is minus one  -- Hailey.

CLICK HERE to unravel the mystery of vanishing Hailey's comet-like disappearance.