Suggestions on how I should handle this

I have an application I've written for a pet sitting service. So someone calls and says they need a pet sit and we take their info and pick a sitter. We call that sitter to see if they can take the job, but if they say no, then we have to change it to a new sitter who can take the job. I want to keep track of who says yes and who says no and make sure we know who the active sitter is for each job. Does anyone have suggestions of a good way to handle this with the database and such? Any thoughts appreciated, Sarah