hinged bed??

i want to have my bed hing up so i can eliminate the filler on the top of my bed all together (and fill the tank from under the bed)... anyone have any pictures or ideas on how that could be done... i was thinking of useing an airbag to actuate the bed... no looking for anything fancy like twisting the bed or things like that, just have the bed hing up tward the back... thank for any ideas...