I have a few partial ideas on this subject but I'm sure there are solid answers out there that people recommend.

I have an array (setup in a datagrid object) which contains a slew of data. Most variables of data are 0/1 binaries which signify if a positive or negative for a given category. I'd like to populate a drop down based on a combination of those variables, which will then change a different variable. For example:

Animal,friendly,small,stinks,hairy,available

Dog,1,1,0,1,1
Cat,1,1,0,1,1
Lizard,0,1,1,0,1
Bird,0,1,1,0,1

I want to add only non-hairy, non-stinky, available animals to my drop down list. Bird and lizard it is! They appear in my drop down. I then choose the bird in that drop down. Well, then the bird is no longer available so I need up update his last variable to a 0 so he won't be in the next query for the same thing?