pack and unpack functions

hey everyone-- I'm trying to take an array and pack() it and then pass it to the next form as a hidden value. Once it gets to the next form I unpack this packed array using the unpack() function the only problem is that I don't know what the parameters are or what they mean and php.net doesn't really help out at all. Is there anyway I can use this funciton or should I try another way of doing this? Thanks, Jay