We consider membranes interacting via short, intermediate and long stickers.
The effects of the intermediate stickers on the lateral phase separation of the
membranes are studied via mean-field approximation. The critical potential
depth of the stickers increases in the presence of the intermediate sticker.
The lateral phase separation of the membrane thus suppressed by the
intermediate stickers. Considering membranes interacting with short and long
stickers, the effect of confinement on the phase behavior of the membranes is
also investigated analytically