arrays as parameters to pl/pgsql functions

Is it possible to use an array as a parameter to a pl/pgsql function. I am
running version 7.3 and don't have the time right now to upgrade.If it is
possible, how do you iterate through the array? For example:

phpVariable[0]=1;
phpVariable[1]=2;
phpVariable[2]=3;

some_pl/pgsql_function(phpVariable?)
how do you access phpVariable[2] within the function?

Thanks.

Julie