my front seal on the automatic tranny popped out. what do i do to keep it in

??MORE to the story?? It just 'popped out'? Was the trans rebuilt recently? Have you already had it out , replaced the seal , reinstalled trans and the seal behind the torque converter cam,e out? Was case inspected and cleaned well? Correct seal? Put in clean and dry , or was a sealer/loc-tite used?